vulnerability / NVI-00002414 / Revision 2
WWBN AVideo's GIF poster fetch bypasses traversal scrubbing and exposes local files through public media URLs
OSV carries this publisher advisory for WWBN/AVideo. This is an aggregated source copy; consult the original publisher and compare update dates.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
7.6 HIGH (3.1)
security-advisories@github.com severity; no combined Null risk score.
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
WWBN/AVideo
source listedECOSYSTEM: introduced 0; last_affected 26.0
## Summary `objects/aVideoEncoderReceiveImage.json.php` allowed an authenticated uploader to fetch attacker-controlled same-origin `/videos/...` URLs, bypass traversal scrubbing, and expose server-local files through the GIF poster storage path. The vulnerable GIF branch could be abused to read local files such as `/etc/passwd` or application source files and republish those bytes through a normal public GIF media URL. ## Details The vulnerable chain was: 1. `objects/aVideoEncoderReceiveImage.json.php` accepted attacker-controlled `downloadURL_gifimage` 2. traversal scrubbing used `str_replace('../', '', ...)`, which was bypassable with overlapping input such as `....//` 3. same-origin `/videos/...` URLs were accepted 4. `url_get_contents()` and `try_get_contents_from_local()` resolved the request into a local filesystem read 5. the fetched bytes were written into the GIF destination 6. invalid GIF cleanup used the wrong variable, so the non-image payload remained on disk This made the GIF poster path a local file disclosure primitive with public retrieval. ## Proof of concept 1. Log in as an uploader and create an owned video row through the normal encoder flow. 2. Send:
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. NIST National Vulnerability Database
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
- NVD lastModified does not establish freshness of every associated CPE record.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-f4f9-627c-jh33 ↗
GitHub Advisory Database via OSV · vendor advisory
Observed . GitHub-origin advisory, CC-BY-4.0; OSV is an aggregate copy, not independent corroboration.
- CVE-2026-39369 ↗
NIST National Vulnerability Database · official catalog
Observed . This product uses data from the NVD API but is not endorsed or certified by the NVD.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 2 ·
Source facts changed; compare the preserved prior revision.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.