Two critical vulnerabilities in its server application, which could allow remote attackers to obtain unauthorized information or cause denial of service once they download a maliciously crafted image file JPEG, have been discovered and repaired by Facebook.
The vulnerabilities they were discovered on HHVM (Virtual HipHop Machine) - a high performance virtual machine open source developed by Facebook for executing programs written in PHP and Hack programming languages.
Since the affected HHVM server application is open source and free, both issues may affect other sites that use HHVM, including Wikipedia , Box and especially those that allow their users to upload images to the server.
Both vulnerabilities are due to a possible "memory overflow" in the HHVM GD extension, when an attacker inserts a custom JPEG image that allows a malicious program to read data beyond its limits. of memory.
CVE-2019-11925: There are insufficient threshold control problems when editing the JPEG APP12 block marker in the GD extension, enabling potential invaders access the off-line memory by maliciously generating invalid JPEG input.
CVE-2019-11926: Insufficient threshold control problems occur when processing M_SOFx markers from JPEG headers in the GD extension, allowing potential intruders to access off-memory by maliciously generating invalid JPEG input.
Both vulnerabilities affect all supported HHVM versions prior to 3.30.9, all versions between 4.0.0 and 4.8.3, all versions between 4.9.0 and 4.15.2, and 4.16.0 to 4.16.3, 4.17 .0 to 4.17.2, 4.18.0, 4.18.1 to 4.19.0.
The HHVM team encountered vulnerabilities with the release of the HHVM versions 4.21.0, 4.20.2, 4.19.1, 4.18.2, 4.17.3, 4.16.4, 4.15.3, 4.8.4 and 3.30.10.
If your site or server also uses HHVM, it is recommended that you update it to the latest version of the software immediately.