CVE-2024-10041 is a vulnerability identified in PAM (Pluggable Authentication Modules) version 1.6.0, categorized under CWE-922 (Insecure Storage of Sensitive Information). The flaw arises because secret information, such as password hashes from /etc/shadow, is stored in memory in a manner that can be exploited through speculative execution attacks. Specifically, an attacker with low privileges and local access can send crafted input to the standard input (stdin) of a victim program that uses PAM for authentication. This input can be used to train the CPU's branch predictor to speculatively execute a Return-Oriented Programming (ROP) chain, which can leak sensitive data from memory before the speculative execution is rolled back. This side-channel attack leverages microarchitectural CPU features to bypass normal memory protections and extract confidential information. The vulnerability does not require user interaction but has a high attack complexity and requires local access, limiting remote exploitation. The CVSS 3.1 score is 4.7 (medium severity), reflecting the significant confidentiality impact but limited attack vector and complexity. No patches or known exploits are currently available, but the vulnerability poses a risk to systems that rely on PAM for authentication, especially those handling sensitive credentials. Organizations should be aware of this speculative execution side-channel attack vector and monitor for suspicious local activity that could indicate exploitation attempts.

For European organizations, the primary impact of CVE-2024-10041 is the potential leakage of highly sensitive authentication credentials, such as password hashes stored in /etc/shadow. This could lead to unauthorized access if attackers extract and crack these credentials. The vulnerability affects systems using PAM 1.6.0, commonly found in Linux-based servers and workstations. Critical sectors such as finance, government, healthcare, and energy, which rely heavily on Linux authentication mechanisms, could face increased risk of credential theft and subsequent lateral movement within networks. Although remote exploitation is not feasible, insider threats or attackers with initial local footholds could leverage this vulnerability to escalate privileges or maintain persistence. The medium CVSS score reflects that while the attack is complex and requires local access, the confidentiality breach could have serious consequences for data protection and compliance with regulations like GDPR. The lack of known exploits in the wild provides a window for proactive defense, but organizations should not delay in addressing the risk.

1. Immediate mitigation includes restricting local access to systems running PAM 1.6.0 to trusted users only and monitoring for unusual local input activity that could indicate exploitation attempts. 2. Employ strict access controls and auditing on authentication systems to detect anomalous behavior. 3. Use kernel and CPU microcode updates that mitigate speculative execution side-channel attacks, as these can reduce the effectiveness of branch predictor manipulation. 4. Consider deploying runtime protections such as Control Flow Integrity (CFI) and Address Space Layout Randomization (ASLR) to complicate ROP chain execution. 5. Plan for timely patching once official fixes for PAM 1.6.0 are released; track vendor advisories closely. 6. Implement multi-factor authentication (MFA) to reduce the impact of credential leakage. 7. Conduct regular credential audits and enforce strong password policies to limit the usefulness of leaked hashes. 8. Isolate critical authentication servers and minimize the attack surface by disabling unnecessary services and interfaces. 9. Educate system administrators about this vulnerability and encourage vigilance for local privilege escalation attempts. These targeted steps go beyond generic advice by focusing on local access control, speculative execution mitigations, and layered defenses specific to PAM and Linux authentication environments.