CVE-2020-25791

Vulnerability

The sized-chunks crate (versions up to and including 0.6.2) contains a soundness vulnerability in its Chunk implementation. When constructing a Chunk via the unit() or pair() methods, the array size is not properly checked against the allocated storage[1][3]. This can result in out-of-bounds memory access or other memory corruption.

Exploitation

Exploitation requires an attacker to control the size parameter passed to these methods, which may be possible if the crate is used in a context where user-supplied data influences chunk construction. No special authentication or network position is required beyond the ability to invoke the vulnerable APIs[2].

Impact

A successful exploit can lead to memory safety violations, including potential arbitrary code execution or data corruption. The RustSec advisory rates the severity as HIGH with a CVSS score of 7.5[3]. Multiple related soundness issues were reported in the same crate.

Mitigation

The sized-chunks repository has been archived by its owner[1], and no patched version is available. Users are advised to avoid using the crate or to rely on alternative libraries. The vulnerability is tracked in the RustSec database and has been assigned CVE-2020-25791.