FreeType: FreeType buffer overflow (CVE-2025-27363) #shorts

Summary

In today's episode, we're diving into CVE-2025-27363, a high-severity vulnerability affecting FreeType, a popular software library used for text rendering. This vulnerability allows for a serious security flaw leading to potential arbitrary code execution and has already been flagged for active exploitation.

Product details

FreeType is a widely-used software library primarily developed to render text using fonts. It is often integrated into a variety of applications across different platforms. The versions affected by this vulnerability are 2.13.0 and below, which are susceptible to security breaches if not updated.

Vulnerability type summary

CVE-2025-27363 is classified as an out-of-bounds write vulnerability, specifically categorized under CWE-787. This type of vulnerability occurs when a program writes data beyond the boundaries of allocated memory, which can lead to unexpected behavior and potential code execution.

Details of the vulnerability

The vulnerability in FreeType arises when attempting to parse font subglyph structures related to TrueType GX and variable font files. The issue emanates from a signed short value being assigned to an unsigned long and subsequently augmented with a static value, which leads to a wrap-around in memory allocation. This results in the allocation of an inadequate heap buffer, permitting the execution of up to 6 signed long integers out of bounds. Such a flaw presents an opportunity for arbitrary code execution, and it has been acknowledged that there may have been real-world exploits leveraging this vulnerability.

Conclusion

To mitigate the risks associated with CVE-2025-27363, it is crucial for users to update FreeType to the latest version, beyond 2.13.0, as these patches address the out-of-bounds write vulnerability. Companies such as SUSE have already released important security updates, reflecting the critical nature of this vulnerability. Stay tuned and stay secure by keeping all your software up to date, especially in light of active exploitation threats.

This chain involves the following actors

This following systems are involved

Attack entry point

Remediation actions

Exploitation actions

• https://www.facebook.com/security/advisories/cve-2025-27363
• [2025-05-06] Google fixed an actively exploited Android flaw, CVE-2025-27363, in its monthly security updates.
• [2025-05-07] Google fixes FreeType vulnerability in Android that may be under limited, targeted exploitation.