CVE-2022-28321 is a critical vulnerability affecting the Linux-PAM package, specifically versions prior to 1.5.2-6.1 for openSUSE Tumbleweed. This vulnerability allows authentication bypass for SSH logins due to a flaw in the pam_access.so module, which fails to restrict login attempts from non-resolvable IP addresses. This flaw enables unauthorized access to systems, bypassing intended security measures.
The CVSS score for this vulnerability is 9.8, indicating a critical severity level. The attack vector is network-based with low complexity, requiring no privileges or user interaction. The implications of this vulnerability are severe, as it impacts confidentiality, integrity, and availability of systems utilizing Linux-PAM, particularly on openSUSE platforms.
Given the potential for widespread exploitation, organizations using affected versions should prioritize patching immediately. The urgency is underscored by the lack of known public exploits but the significant risk posed by this vulnerability.
The vulnerability was first published on September 19, 2022, and has been classified under CWE-287, which pertains to improper authentication. While the issue mainly affects openSUSE Tumbleweed and openSUSE Factory, it does not impact Linux-PAM upstream.
Vulnerability Details
The official description states that the Linux-PAM package before version 1.5.2-6.1 for openSUSE Tumbleweed allows authentication bypass for SSH logins. The pam_access.so module does not correctly restrict login if a user tries to connect from an IP address that is not resolvable via DNS. In such conditions, a user with denied access to a machine can still gain entry.
The CVSS 3.1 score of 9.8 places this vulnerability in the critical category, reflecting its potential impact on systems. The vulnerability has been reported with a primary classification of CWE-287.
Technical Analysis
The root cause of this vulnerability lies in the pam_access.so module's inability to appropriately restrict access based on DNS resolvability. The attack vector is primarily network-based, allowing attackers to exploit this flaw without needing physical access to the system.
Attack complexity is rated as low, with no privileges required to exploit this vulnerability, and user interaction is not necessary. The impacts on confidentiality, integrity, and availability are all rated as high, indicating a significant threat to organizations that do not apply the necessary patches.
Risk & Impact Analysis
Organizations using openSUSE Tumbleweed or Factory are at risk of unauthorized access due to this vulnerability. The ability for an attacker to bypass authentication can lead to data breaches and further exploitation of the system. The blast radius is extensive, potentially affecting all users with SSH access.
Given the critical nature of this vulnerability and its exploitation potential, organizations should address it in their priority patch cycle. The urgency is compounded by the high CVSS score, indicating that remediation should be treated as a top priority.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The affected product is the Linux-PAM package, specifically all versions prior to 1.5.2-6.1. Organizations should verify their installations to ensure they are not using vulnerable versions.
Mitigation & Remediation
To mitigate this vulnerability, organizations should upgrade to the latest version of the Linux-PAM package, specifically 1.5.2-6.1 or later. If immediate patching is not feasible, consider implementing network controls to restrict access based on IP address resolution.
Organizations should also consider conducting a security assessment to evaluate their exposure to similar vulnerabilities. For further assistance, organizations can explore the benefits of penetration testing to strengthen their overall security posture.
Detection Guidance
Organizations should monitor logs for unusual login attempts and access from non-resolvable IP addresses. Behavioral anomalies such as repeated access denials followed by successful logins should be closely examined.
AppSecure Threat Intelligence Insight
The long-term significance of this vulnerability lies in its potential to undermine security practices in environments using outdated authentication mechanisms. Security teams should prioritize understanding and mitigating similar vulnerabilities in their systems.
This incident highlights the need for continuous monitoring and proactive security measures. Organizations are encouraged to adopt penetration testing methodologies as part of their security strategy.
Furthermore, leveraging comprehensive vulnerability management programs can help organizations mitigate risks associated with similar vulnerabilities in the future.
Lastly, security teams should collaborate with incident response to ensure a swift response to any detected anomalies or breaches related to this vulnerability.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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