CVE-2024-43399

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

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.

Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files. Typical impact: unauthorized file read or write outside the intended directory.

CVE-2024-43399 has a CVSS score of 8.0 (High). The vector is network-reachable, low privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (4.0.7); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2024-43399? CVE-2024-43399 is a high-severity path traversal vulnerability in mobsf (pip), affecting versions <= 4.0.6. It is fixed in 4.0.7. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
2. How severe is CVE-2024-43399? CVE-2024-43399 has a CVSS score of 8.0 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of mobsf are affected by CVE-2024-43399? mobsf (pip) versions <= 4.0.6 is affected.
4. Is there a fix for CVE-2024-43399? Yes. CVE-2024-43399 is fixed in 4.0.7. Upgrade to this version or later.
5. Is CVE-2024-43399 exploitable, and should I be worried? Whether CVE-2024-43399 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2024-43399 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2024-43399? Upgrade mobsf to 4.0.7 or later.