CVE-2021-45960 is a high-severity vulnerability affecting Expat (also known as libexpat) versions prior to 2.4.3. This vulnerability allows an attacker to cause realloc misbehavior by executing a left shift by 29 or more places within the storeAtts function in xmlparse.c. The consequences of this flaw are severe, with a CVSS score of 8.8, indicating a high level of risk to organizations.
The risk to organizations includes potential unauthorized access, data corruption, and system instability, making it critical for affected entities to act swiftly. The vulnerability is classified under CWE-682, indicating an issue with improper handling of memory allocation.
As of now, there is no known exploit in the wild, but the potential for exploitation is high given the nature of the vulnerability. It is vital for organizations that utilize Expat, particularly those in networking environments, to prioritize the patching of this vulnerability.
Organizations should prioritize patching immediately. The urgency for remediation is underscored by the vulnerability's high impact on confidentiality, integrity, and availability.
Vulnerability Details
The official CVE description states: 'In Expat (aka libexpat) before 2.4.3, a left shift by 29 (or more) places in the storeAtts function in xmlparse.c can lead to realloc misbehavior (e.g., allocating too few bytes, or only freeing memory).'
The vulnerability affects multiple versions of Expat, as well as products from vendors such as Tenable, NetApp, Siemens, and Debian. The CVSS 3.1 score is 8.8, indicating high severity due to its potential impact on confidentiality, integrity, and availability.
Published on January 1, 2022, the vulnerability has been classified under CWE-682. Organizations using affected versions are advised to upgrade to version 2.4.3 or later to mitigate risks.
Technical Analysis
The root cause of CVE-2021-45960 lies in the improper handling of memory allocation within the Expat library. The attack vector is network-based, allowing remote exploitation with low attack complexity. Attackers require low privileges and no user interaction is necessary to exploit this vulnerability.
This vulnerability has a high impact on confidentiality, integrity, and availability, making it a critical concern for organizations that rely on Expat for XML parsing. The lack of user interaction required for exploitation increases the potential attack surface, and organizations must remain vigilant against potential threats.
Risk & Impact Analysis
The real-world deployment risk associated with CVE-2021-45960 is significant, particularly for organizations using Expat in critical applications. The blast radius is extensive, given the library's widespread usage. Organizations must understand that this vulnerability can lead to severe impacts, including unauthorized data access and system failures.
The urgency of addressing this vulnerability is underscored by its CVSS score of 8.8. Organizations should address this vulnerability in their priority patch cycle, given the high potential for exploitation and the significant risks it poses.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | Yes |
Public PoC | Yes |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The vulnerability affects all versions of Expat prior to 2.4.3. Other affected products include specific versions of Tenable Nessus, Debian Linux (10.0 and 11.0), Siemens Sinema Remote Connect Server, and various NetApp components. Organizations should ensure they are running updated versions to mitigate risks.
Mitigation & Remediation
To mitigate CVE-2021-45960, organizations should upgrade Expat to version 2.4.3 or later. For those using affected products, refer to vendor advisories for specific patch information. If patches are not readily available, implementing configuration hardening and network controls can help reduce exposure.
Organizations should validate remediation through penetration testing to identify similar weaknesses.
Detection Guidance
To detect potential exploitation of CVE-2021-45960, organizations should monitor logs for unusual memory allocation patterns, unexpected application behavior, and network traffic anomalies. Behavioral monitoring can help identify exploitation attempts.
AppSecure Threat Intelligence Insight
CVE-2021-45960 exemplifies vulnerabilities that arise from improper memory management, highlighting the need for rigorous code audits and testing. Security teams should learn from this incident to implement stricter validation and checks within their software development lifecycle.
It's crucial for organizations to stay updated on vulnerabilities in libraries they utilize, as these can significantly impact their overall security posture. Regularly reviewing and updating third-party dependencies is essential.
For organizations using Expat or related products, consider engaging in penetration testing methodology to enhance their security measures.
In conclusion, CVE-2021-45960 serves as a reminder of the vulnerabilities present in widely used libraries. Organizations must maintain vigilance and proactively manage their security strategies to protect against potential exploits.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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