A vulnerability has been identified in the FreeType font rendering library (CVE-2025-27363), which could potentially allow code execution when processing specially crafted variable font files or TrueType GX fonts. The issue affects FreeType releases up to and including version 2.13.0 and has been resolved in version 2.13.1 (June 2023). It is believed that this vulnerability has been previously exploited for conducting attacks.
The vulnerability is caused by a buffer overflow that occurs when parsing subglyph structures in fonts. The overflow occurs due to assigning a value of type ‘unsigned long’ to a variable of type ‘signed short’, which is involved in the buffer size calculation, resulting in an integer overflow and allocation of an incorrectly sized buffer. Subsequently, at least 6 signed integers of type ‘long’ are written out of this buffer.
You can track updates in the distributions on the following pages: Debian, Ubuntu, RHEL, SUSE/openSUSE, Fedora, Arch, FreeBSD. Based on the statistics of used versions, vulnerable FreeType versions are included in distributions such as Amazon Linux 2, Debian stable / Devuan, RHEL 8 and 9 (+ CentOS Stream and derivative distributions), GNU Guix, Mageia, OpenMandriva, openSUSE Leap, Slackware, and Ubuntu 22.04.
Source: opennet.ru
