CVE-2023-6129

A flaw was found in in the POLY1305 MAC (message authentication code) implementation in OpenSSL, affecting applications running on PowerPC CPU-based platforms that utilize vector instructions, and has the potential to corrupt the internal state of these applications. If an attacker can manipulate the utilization of the POLY1305 MAC algorithm, it may lead to the corruption of the application state, resulting in various application-dependent consequences, often resulting in a crash and leading to a denial of service.

This vulnerability is categorized as having a Low severity due to the limited scope of its potential impact and the specific conditions required for exploitation. The vulnerability arises in the POLY1305 MAC implementation within OpenSSL on PowerPC CPUs, affecting newer processors supporting PowerISA 2.07 instructions. The issue involves the restoration of vector registers in a different order than they are saved, potentially corrupting application state upon return to the caller. The impact varies, contingent on the application's reliance on non-volatile XMM registers, ranging from incorrect calculations to potential denial of service. However, the practical exploitation of this vulnerability requires an attacker to influence the use of the POLY1305 MAC algorithm. Given the specific conditions needed for exploitation and the absence of concrete instances of affected applications, the overall risk is assessed as low. Additionally, the severity is tempered by the assumption that the most likely outcome is limited to incorrect results in application-dependent calculations or crashes, rather than enabling a full compromise of the application process.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.