Description
Viber for iOS through 29.4.0.24 fails to validate the logical screen width and height in received GIF headers, allowing attackers to crash the app. Attackers can send a crafted GIF with zero dimensions that triggers an uncaught NSInternalInconsistencyException, aborting the app with SIGABRT when opened.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Rakuten Viber | Viber for iOS | ≤ 29.4.0.24 | — |
References
- https://www.zeroscience.mk/en/vulnerabilities/ZSL-2026-6039.php third-party-advisory
- https://www.viber.com product
- VulnCheck Advisory: Viber for iOS through 29.4.0.24 Denial of Service via Malformed GIF third-party-advisory