CVE-2025-1866: Undefined Behavior Due to Out-of-Bounds Pointer Arithmetic in libwebsockets
Description
Improper Restriction of Operations within the Bounds of a Memory Buffer vulnerability in warmcat libwebsockets allows Pointer Manipulation, potentially leading to out-of-bounds memory access. This issue affects libwebsockets before 4.3.4 and is present in code built specifically for the Win32 platform.
By default, the affected code is not executed unless one of the following conditions is met:
LWS_WITHOUT_EXTENSIONS (default ON) is manually set to OFF in CMake.
LWS_WITH_HTTP_STREAM_COMPRESSION (default OFF) is manually set to ON in CMake.
Despite these conditions, when triggered in affected configurations, this vulnerability may allow attackers to manipulate pointers, potentially leading to memory corruption or unexpected behavior.
Classification
CVE ID: CVE-2025-1866
CVSS Base Severity: CRITICAL
CVSS Base Score: 10.0
CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
Affected Products
Vendor: warmcat
Product: libwebsockets
Exploit Prediction Scoring System (EPSS)
EPSS Score: 0.05% (probability of being exploited)
EPSS Percentile: 13.64% (scored less or equal to compared to others)
EPSS Date: 2025-04-01 (when was this score calculated)
References
https://nvd.nist.gov/vuln/detail/CVE-2025-1866https://github.com/warmcat/libwebsockets/commit/3f7c79fd57338aca1bf4a1b1f24e324b80d36265