ghsa-4hh3-vj32-gr6j
Vulnerability from github
Published
2024-08-19 17:29
Modified
2024-08-19 17:29
Severity ?
8.0 (High) - CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
8.6 (High) - CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Summary
Mobile Security Framework (MobSF) has a Zip Slip Vulnerability in .a Static Library Files
Details

Summary

Upon reviewing the MobSF source code, I identified a flaw in the Static Libraries analysis section. Specifically, during the extraction of .a extension files, the measure intended to prevent Zip Slip attacks is improperly implemented.

Since the implemented measure can be bypassed, the vulnerability allows an attacker to extract files to any desired location within the server running MobSF.

Details

Upon examining lines 183-192 of the mobsf/StaticAnalyzer/views/common/shared_func.py file, it is observed that there is a mitigation against Zip Slip attacks implemented as a.decode('utf-8', 'ignore').replace('../', '').replace('..\\', ''). However, this measure can be bypassed using sequences like ....//....//....//. Since the replace operation is not recursive, this sequence is transformed into ../../../ after the replace operation, allowing files to be written to upper directories.

For the proof of concept, I created an .a archive file that renders MobSF unusable by writing an empty file with the same name over the database located at /home/mobsf/.MobSF/db.sqlite3.

I am including the binary used for the POC named poc.VULN. To test it, you need to rename this binary to poc.a.

Warning: As soon as you scan this file with MobSF, the database will be deleted, rendering MobSF unusable.

PoC Binary File (poc.VULN)

PoC

https://github.com/user-attachments/assets/3225ccb0-cb00-47a5-8305-37a40ca1ae7f

Impact

When a malicious .a file is scanned with MobSF, a critical vulnerability is present as it allows files to be extracted to any location on the server where MobSF is running. In this POC, I deleted the database, but it is also possible to achieve RCE by overwriting binaries of certain tools or by overwriting the /etc/passwd file.

Show details on source website

To clipboard 

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 4.0.6"
      },
      "package": {
        "ecosystem": "PyPI",
        "name": "mobsf"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.0.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2024-43399"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-22",
      "CWE-23"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2024-08-19T17:29:52Z",
    "nvd_published_at": "2024-08-19T15:15:09Z",
    "severity": "HIGH"
  },
  "details": "### Summary\nUpon reviewing the MobSF source code, I identified a flaw in the Static Libraries analysis section. Specifically, during the extraction of .a extension files, the measure intended to prevent Zip Slip attacks is improperly implemented.\n\nSince the implemented measure can be bypassed, the vulnerability allows an attacker to extract files to any desired location within the server running MobSF.\n\n### Details\n\nUpon examining lines 183-192 of the `mobsf/StaticAnalyzer/views/common/shared_func.py` file, it is observed that there is a mitigation against Zip Slip attacks implemented as `a.decode(\u0027utf-8\u0027, \u0027ignore\u0027).replace(\u0027../\u0027, \u0027\u0027).replace(\u0027..\\\\\u0027, \u0027\u0027)`. However, this measure can be bypassed using sequences like `....//....//....//`. Since the replace operation is not recursive, this sequence is transformed into `../../../` after the replace operation, allowing files to be written to upper directories.\n\n\u003cimg width=\"448\" alt=\"image\" src=\"https://github.com/user-attachments/assets/fadf4bcc-1a92-4655-b66a-5349278ad9c5\"\u003e\n\n\nFor the proof of concept, I created an .a archive file that renders MobSF unusable by writing an empty file with the same name over the database located at `/home/mobsf/.MobSF/db.sqlite3`.\n\n\u003cimg width=\"300\" alt=\"poc a_1\" src=\"https://github.com/user-attachments/assets/54acf101-3931-401f-9970-a0934265eecb\"\u003e\n\n\nI am including the binary used for the POC named `poc.VULN`. To test it, you need to rename this binary to `poc.a`.\n\n **Warning:** As soon as you scan this file with MobSF, the database will be deleted, rendering MobSF unusable.\n\nPoC Binary File ([poc.VULN](https://drive.google.com/file/d/1K2eHYIZ1hUbs-Vi5zhKAKecnd0nDB8lO/view?usp=share_link))\n\n### PoC\n\n\nhttps://github.com/user-attachments/assets/3225ccb0-cb00-47a5-8305-37a40ca1ae7f\n\n\n\n### Impact\n\nWhen a malicious .a file is scanned with MobSF, a critical vulnerability is present as it allows files to be extracted to any location on the server where MobSF is running. In this POC, I deleted the database, but it is also possible to achieve RCE by overwriting binaries of certain tools or by overwriting the /etc/passwd file.\n",
  "id": "GHSA-4hh3-vj32-gr6j",
  "modified": "2024-08-19T17:29:52Z",
  "published": "2024-08-19T17:29:52Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/MobSF/Mobile-Security-Framework-MobSF/security/advisories/GHSA-4hh3-vj32-gr6j"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-43399"
    },
    {
      "type": "WEB",
      "url": "https://github.com/MobSF/Mobile-Security-Framework-MobSF/commit/cc625fe8430f3437a473e82aa2966d100a4dc883"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/MobSF/Mobile-Security-Framework-MobSF"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Mobile Security Framework (MobSF) has a Zip Slip Vulnerability in .a Static Library Files"
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.