A heap-based buffer overflow was found in the __vsyslog_internal function of the glibc library. This function is called by the syslog and vsyslog functions. This issue occurs when the openlog function was not called, or called with the ident argument set to NULL, and the program name (the basename of argv[0]) is bigger than 1024 bytes, resulting in an application crash or local privilege escalation. This issue affects glibc 2.36 and newer.
The vulnerability has been assigned a CVSS score of 8.4, indicating a high severity level. This is significant because it allows attackers to exploit the vulnerability without requiring elevated privileges, potentially leading to serious consequences for affected systems.
Risk to organizations includes application crashes and the possibility of local privilege escalation. Organizations should prioritize patching immediately.
Currently, there is no public exploit confirmed for this vulnerability, but it has been flagged as having a high exploitability index. Hence, organizations using vulnerable versions of the glibc library must take immediate action to mitigate risks.
Vulnerability Details
This vulnerability allows for a heap-based buffer overflow in the GNU glibc library, specifically in the __vsyslog_internal function. The CVSS score of 8.4 classifies this vulnerability as high severity due to its potential impact on confidentiality, integrity, and availability.
The affected versions are glibc 2.36 and newer. The vulnerability was published on January 31, 2024.
Technical Analysis
The root cause of this vulnerability stems from improper handling of buffer sizes in the __vsyslog_internal function when the program name exceeds 1024 bytes. This can lead to a crash or exploitation by an unauthorized user.
The attack vector is local, requiring the attacker to have access to the system. The complexity of the attack is low, as no special privileges or user interactions are required.
The impacts on confidentiality, integrity, and availability are all classified as high, indicating significant potential damage if exploited.
Risk & Impact Analysis
Organizations using the affected versions of glibc face substantial risks, including application crashes and potential privilege escalation. The blast radius could extend to critical applications relying on the glibc library.
Given the CVSS score and the potential for exploitation, organizations should address this vulnerability in their priority patch cycle.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | Yes |
Public PoC | Yes |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
This vulnerability affects the following versions of glibc and Fedora: glibc versions 2.36 through 2.38 inclusive, and Fedora versions 38 and 39.
Mitigation & Remediation
Organizations should ensure they update their glibc library to a patched version immediately. For those unable to patch, consider configuration hardening and applying network controls to limit exposure.
Monitoring for unusual behavior around the syslog function is also recommended to detect potential exploitation attempts.
Penetration testing can help identify whether your systems are vulnerable to this issue.
Detection Guidance
Organizations should monitor logs for anomalies related to syslog and vsyslog calls, particularly around the use of overly long program names.
Behavioral anomalies in applications using glibc should be investigated promptly.
AppSecure Threat Intelligence Insight
The significance of this vulnerability lies in the potential for widespread impacts, given the usage of glibc across numerous applications and systems.
This vulnerability represents a critical lesson on the importance of validating input sizes and handling errors appropriately.
Security teams should review their coding practices and ensure robust logging mechanisms are in place to catch such vulnerabilities before they are exploited.
Understanding secure coding practices can provide insights for developers to avoid similar vulnerabilities in the future.
Implementing a robust vulnerability management program will also help organizations stay ahead of potential threats.
API penetration testing should be part of the overall security strategy to mitigate such vulnerabilities.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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