CWE-703
DiscouragedImproper Check or Handling of Exceptional Conditions
Abstraction: Pillar · Status: Incomplete
The product does not properly anticipate or handle exceptional conditions that rarely occur during normal operation of the product.
225 vulnerabilities reference this CWE, most recent first.
GHSA-X64V-PQ34-G3CQ
Vulnerability from github – Published: 2024-07-21 09:30 – Updated: 2024-08-30 21:31Unitronics Vision PLC – CWE-703: Improper Check or Handling of Exceptional Conditions may allow denial of service
{
"affected": [],
"aliases": [
"CVE-2024-38435"
],
"database_specific": {
"cwe_ids": [
"CWE-703"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-07-21T08:15:05Z",
"severity": "MODERATE"
},
"details": "Unitronics Vision PLC \u2013\u00a0CWE-703: Improper Check or Handling of Exceptional Conditions may allow denial of service",
"id": "GHSA-x64v-pq34-g3cq",
"modified": "2024-08-30T21:31:40Z",
"published": "2024-07-21T09:30:32Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-38435"
},
{
"type": "WEB",
"url": "https://www.gov.il/en/Departments/faq/cve_advisories"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-X6CR-MQ53-CC76
Vulnerability from github – Published: 2026-02-10 14:33 – Updated: 2026-02-10 19:56Summary
The cookies property in emmett_core.http.wrappers.Request does not handle
CookieError exceptions when parsing malformed Cookie headers. This allows
unauthenticated attackers to trigger HTTP 500 errors and cause denial of service.
Details
Location: emmett_core/http/wrappers/__init__.py (line 64)
Vulnerable Code:
@cachedprop
def cookies(self) -> SimpleCookie:
cookies: SimpleCookie = SimpleCookie()
for cookie in self.headers.get("cookie", "").split(";"):
cookies.load(cookie) # No exception handling
return cookies
PoC
Sending cookies containing special characters such as /(){} will result in insufficient error handling and a server error.
$ curl -w "\nTime: %{time_total}s\n" http://localhost:8000/ -H "Cookie:/security=test"
Internal error
Time: 0.024363s
After the same error occurs several times, the server cannot process it normally.
$ curl -w "\nTime: %{time_total}s\n" http://localhost:8000/ -H "Cookie:(security=test"
Internal error
Time: 60.069334s
$ curl -w "\nTime: %{time_total}s\n" http://localhost:8000/ -H "Cookie:security=test"
Internal error
Time: 60.074031s
This is server log.
[2026-02-03 08:23:40,541] ERROR in handlers: Application exception:
Traceback (most recent call last):
File "/home/geonwoo/.local/lib/python3.13/site-packages/emmett/rsgi/handlers.py", line 70, in dynamic_handler
http = await self.router.dispatch(request, response)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/geonwoo/.local/lib/python3.13/site-packages/emmett_core/routing/router.py", line 240, in dispatch
return await match.dispatch(reqargs, response)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/geonwoo/.local/lib/python3.13/site-packages/emmett_core/routing/dispatchers.py", line 57, in dispatch
await self._parallel_flow(self.flow_open)
File "/home/geonwoo/.local/lib/python3.13/site-packages/emmett_core/routing/dispatchers.py", line 17, in _parallel_flow
raise task.exception()
File "/home/geonwoo/.local/lib/python3.13/site-packages/emmett_core/sessions.py", line 102, in open_request
if self.cookie_name in self.current.request.cookies:
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/geonwoo/.local/lib/python3.13/site-packages/emmett_core/utils.py", line 37, in __get__
obj.__dict__[self.__name__] = rv = self.fget(obj)
~~~~~~~~~^^^^^
File "/home/geonwoo/.local/lib/python3.13/site-packages/emmett_core/http/wrappers/__init__.py", line 64, in cookies
cookies.load(cookie)
~~~~~~~~~~~~^^^^^^^^
File "/usr/lib/python3.13/http/cookies.py", line 516, in load
self.__parse_string(rawdata)
~~~~~~~~~~~~~~~~~~~^^^^^^^^^
File "/usr/lib/python3.13/http/cookies.py", line 580, in __parse_string
self.__set(key, rval, cval)
~~~~~~~~~~^^^^^^^^^^^^^^^^^
File "/usr/lib/python3.13/http/cookies.py", line 472, in __set
M.set(key, real_value, coded_value)
~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/python3.13/http/cookies.py", line 335, in set
raise CookieError('Illegal key %r' % (key,))
http.cookies.CookieError: Illegal key '/security'
Impact
This vulnerability allows unauthenticated attackers to cause denial of service and performance degradation by sending malformed Cookie headers. After this vulnerability occurs, we expect it to be difficult to use the normal service.
patch
/emmett_core/http/wrappers/__init__.py
- from http.cookies import SimpleCookie
+ from http.cookies import SimpleCookie, CookieError # add CookieError
...
...
@cachedprop
def cookies(self) -> SimpleCookie:
cookies: SimpleCookie = SimpleCookie()
for cookie in self.headers.get("cookie", "").split(";"):
- cookies.load(cookie)
+ try:
+ cookies.load(cookie)
+ except CookieError:
+ continue
return cookies
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 1.3.10"
},
"package": {
"ecosystem": "PyPI",
"name": "emmett-core"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1.3.11"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-25577"
],
"database_specific": {
"cwe_ids": [
"CWE-248",
"CWE-703"
],
"github_reviewed": true,
"github_reviewed_at": "2026-02-10T14:33:15Z",
"nvd_published_at": "2026-02-10T18:16:37Z",
"severity": "HIGH"
},
"details": "### Summary\nThe `cookies` property in `emmett_core.http.wrappers.Request` does not handle \n`CookieError` exceptions when parsing malformed Cookie headers. This allows \nunauthenticated attackers to trigger HTTP 500 errors and cause denial of service.\n\n\n### Details\n\n**Location:** `emmett_core/http/wrappers/__init__.py` (line 64)\n\n**Vulnerable Code:**\n```python\n@cachedprop\ndef cookies(self) -\u003e SimpleCookie:\n cookies: SimpleCookie = SimpleCookie()\n for cookie in self.headers.get(\"cookie\", \"\").split(\";\"):\n cookies.load(cookie) # No exception handling\n return cookies\n```\n\n### PoC\nSending cookies containing special characters such as /(){} will result in insufficient error handling and a server error.\n```bash\n$ curl -w \"\\nTime: %{time_total}s\\n\" http://localhost:8000/ -H \"Cookie:/security=test\"\nInternal error\nTime: 0.024363s\n```\nAfter the same error occurs several times, the server cannot process it normally.\n```bash\n$ curl -w \"\\nTime: %{time_total}s\\n\" http://localhost:8000/ -H \"Cookie:(security=test\"\nInternal error\nTime: 60.069334s\n\n$ curl -w \"\\nTime: %{time_total}s\\n\" http://localhost:8000/ -H \"Cookie:security=test\"\nInternal error\nTime: 60.074031s\n```\n\nThis is server log.\n```bash\n[2026-02-03 08:23:40,541] ERROR in handlers: Application exception:\nTraceback (most recent call last):\n File \"/home/geonwoo/.local/lib/python3.13/site-packages/emmett/rsgi/handlers.py\", line 70, in dynamic_handler\n http = await self.router.dispatch(request, response)\n ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\n File \"/home/geonwoo/.local/lib/python3.13/site-packages/emmett_core/routing/router.py\", line 240, in dispatch\n return await match.dispatch(reqargs, response)\n ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\n File \"/home/geonwoo/.local/lib/python3.13/site-packages/emmett_core/routing/dispatchers.py\", line 57, in dispatch\n await self._parallel_flow(self.flow_open)\n File \"/home/geonwoo/.local/lib/python3.13/site-packages/emmett_core/routing/dispatchers.py\", line 17, in _parallel_flow\n raise task.exception()\n File \"/home/geonwoo/.local/lib/python3.13/site-packages/emmett_core/sessions.py\", line 102, in open_request\n if self.cookie_name in self.current.request.cookies:\n ^^^^^^^^^^^^^^^^^^^^^^^^^^^^\n File \"/home/geonwoo/.local/lib/python3.13/site-packages/emmett_core/utils.py\", line 37, in __get__\n obj.__dict__[self.__name__] = rv = self.fget(obj)\n ~~~~~~~~~^^^^^\n File \"/home/geonwoo/.local/lib/python3.13/site-packages/emmett_core/http/wrappers/__init__.py\", line 64, in cookies\n cookies.load(cookie)\n ~~~~~~~~~~~~^^^^^^^^\n File \"/usr/lib/python3.13/http/cookies.py\", line 516, in load\n self.__parse_string(rawdata)\n ~~~~~~~~~~~~~~~~~~~^^^^^^^^^\n File \"/usr/lib/python3.13/http/cookies.py\", line 580, in __parse_string\n self.__set(key, rval, cval)\n ~~~~~~~~~~^^^^^^^^^^^^^^^^^\n File \"/usr/lib/python3.13/http/cookies.py\", line 472, in __set\n M.set(key, real_value, coded_value)\n ~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\n File \"/usr/lib/python3.13/http/cookies.py\", line 335, in set\n raise CookieError(\u0027Illegal key %r\u0027 % (key,))\nhttp.cookies.CookieError: Illegal key \u0027/security\u0027\n```\n\n### Impact\nThis vulnerability allows unauthenticated attackers to cause denial of service \nand performance degradation by sending malformed Cookie headers. \nAfter this vulnerability occurs, we expect it to be difficult to use the normal service.\n\n\n\n### patch \n`/emmett_core/http/wrappers/__init__.py`\n```python\n- from http.cookies import SimpleCookie \n+ from http.cookies import SimpleCookie, CookieError # add CookieError\n...\n...\n @cachedprop\n def cookies(self) -\u003e SimpleCookie:\n cookies: SimpleCookie = SimpleCookie()\n for cookie in self.headers.get(\"cookie\", \"\").split(\";\"):\n- cookies.load(cookie)\n+ try:\n+ cookies.load(cookie)\n+ except CookieError:\n+ continue\n return cookies\n```",
"id": "GHSA-x6cr-mq53-cc76",
"modified": "2026-02-10T19:56:59Z",
"published": "2026-02-10T14:33:15Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/emmett-framework/core/security/advisories/GHSA-x6cr-mq53-cc76"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-25577"
},
{
"type": "WEB",
"url": "https://github.com/emmett-framework/core/commit/9557ea23a27cbadf7774d8bca6bbe4b54fa8a3ec"
},
{
"type": "WEB",
"url": "https://github.com/emmett-framework/core/commit/c126757133e118119a280b58f3bb345b1c9a8a2a"
},
{
"type": "PACKAGE",
"url": "https://github.com/emmett-framework/core"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "Emmett-Core: Unhandled CookieError Exception Causing Denial of Service"
}
GHSA-XMHM-HHWR-F9FP
Vulnerability from github – Published: 2026-07-15 18:31 – Updated: 2026-08-14 21:31As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco RoomOS engineering team has conducted a comprehensive internal security review. This review resulted in a software hardening release that addresses multiple internally discovered vulnerabilities.
The vulnerabilities tracked by CVE-2026-20187 are related to improper handling of exceptional conditions that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-703.
{
"affected": [],
"aliases": [
"CVE-2026-20187"
],
"database_specific": {
"cwe_ids": [
"CWE-703"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-07-15T17:16:47Z",
"severity": "HIGH"
},
"details": "As part of Cisco\u0027s ongoing commitment to proactive security and product quality, the Cisco RoomOS engineering team has conducted a comprehensive internal security review. This review resulted in a software hardening release that addresses multiple internally discovered vulnerabilities.\n\nThe vulnerabilities tracked by CVE-2026-20187 are related to improper handling of exceptional conditions that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-703.",
"id": "GHSA-xmhm-hhwr-f9fp",
"modified": "2026-08-14T21:31:09Z",
"published": "2026-07-15T18:31:57Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-20187"
},
{
"type": "WEB",
"url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-hardening-roomos-AqNMbEq"
},
{
"type": "WEB",
"url": "https://www.cve.org/Media/News/item/blog/2026/06/16/Preserving-Vulnerability-Level-Identification"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-XR72-MPJ5-G8P2
Vulnerability from github – Published: 2025-09-05 18:31 – Updated: 2025-09-05 21:32In multiple functions of DexUseManagerLocal.java, there is a possible way to crash system server due to a logic error in the code. This could lead to local permanent denial of service with no additional execution privileges needed. User interaction is not needed for exploitation.
{
"affected": [],
"aliases": [
"CVE-2025-26456"
],
"database_specific": {
"cwe_ids": [
"CWE-703"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-09-04T18:15:45Z",
"severity": "MODERATE"
},
"details": "In multiple functions of DexUseManagerLocal.java, there is a possible way to crash system server due to a logic error in the code. This could lead to local permanent denial of service with no additional execution privileges needed. User interaction is not needed for exploitation.",
"id": "GHSA-xr72-mpj5-g8p2",
"modified": "2025-09-05T21:32:36Z",
"published": "2025-09-05T18:31:18Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-26456"
},
{
"type": "WEB",
"url": "https://android.googlesource.com/platform/art/+/06a99377e368b688dbeb4e6bb11b6e1dfca8bb70"
},
{
"type": "WEB",
"url": "https://android.googlesource.com/platform/art/+/1aedae6e1049aa794b3554183bf07634c8fa291b"
},
{
"type": "WEB",
"url": "https://android.googlesource.com/platform/art/+/3c76194d116bad95e11bda345feaedda6c02c8b4"
},
{
"type": "WEB",
"url": "https://source.android.com/security/bulletin/2025-06-01"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-XX9Q-649R-GP4M
Vulnerability from github – Published: 2025-08-27 00:31 – Updated: 2025-08-27 15:33In multiple functions of hyp-main.c, there is a possible privilege escalation due to a logic error in the code. This could lead to local information disclosure with no additional execution privileges needed. User interaction is not needed for exploitation.
{
"affected": [],
"aliases": [
"CVE-2025-22413"
],
"database_specific": {
"cwe_ids": [
"CWE-703"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-08-26T23:15:34Z",
"severity": "MODERATE"
},
"details": "In multiple functions of hyp-main.c, there is a possible privilege escalation due to a logic error in the code. This could lead to local information disclosure with no additional execution privileges needed. User interaction is not needed for exploitation.",
"id": "GHSA-xx9q-649r-gp4m",
"modified": "2025-08-27T15:33:15Z",
"published": "2025-08-27T00:31:16Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-22413"
},
{
"type": "WEB",
"url": "https://android.googlesource.com/kernel/common/+/1a3366f0d3d9b94a8c025d9863edc3b427435c4c"
},
{
"type": "WEB",
"url": "https://android.googlesource.com/kernel/common/+/add3d68602a0c48ed2d5659f0cf26d869776ab35"
},
{
"type": "WEB",
"url": "https://source.android.com/security/bulletin/2025-03-01"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
"type": "CVSS_V3"
}
]
}
No mitigation information available for this CWE.
No CAPEC attack patterns related to this CWE.