CVE-2021-39275 is a critical vulnerability affecting Apache HTTP Server versions 2.4.48 and earlier. This vulnerability allows buffer overflow when the function ap_escape_quotes() is provided with malicious input. Although no included modules pass untrusted data to these functions, third-party or external modules may. This makes the vulnerability particularly concerning as it can lead to serious security implications.
With a CVSS score of 9.8, this vulnerability is classified as critical. Organizations using affected versions are at a high risk as this vulnerability can lead to potential unauthorized access, data integrity issues, and even service disruptions.
Given its severity, organizations must prioritize patching immediately to protect against exploitation attempts that leverage this vulnerability.
The vulnerability was published on September 16, 2021, and is currently not listed in the Known Exploited Vulnerabilities (KEV) catalog. However, given its critical nature, organizations should remain vigilant against potential exploitation in the wild.
In conclusion, the urgency of addressing CVE-2021-39275 cannot be overstated. Organizations must act swiftly to mitigate risks associated with this critical vulnerability.
Vulnerability Details
The vulnerability description states that ap_escape_quotes() may write beyond the end of a buffer when given malicious input. This issue affects Apache HTTP Server 2.4.48 and earlier versions. The vulnerability is classified under CWE-787, which pertains to improper bounds checking.
Technical Analysis
The root cause of this vulnerability lies in the improper handling of input within the ap_escape_quotes() function. Specifically, this function can be manipulated by malicious actors to write beyond allocated buffers, potentially leading to arbitrary code execution or crashes.
The attack vector is network-based, with low attack complexity and no privileges required for exploitation. Additionally, user interaction is not needed, which increases the risk of successful attacks.
The impacts of this vulnerability include high confidentiality, integrity, and availability impacts, making it crucial for organizations to understand its implications.
Risk & Impact Analysis
Risk to organizations includes potential unauthorized access to sensitive information, integrity violations, and denial of service within affected systems. The blast radius could extend to any system utilizing the vulnerable versions of the Apache HTTP Server, making this a significant threat.
The urgency of addressing this critical vulnerability is heightened by its CVSS score of 9.8, which reflects the severe risk it poses.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
Affected versions include Apache HTTP Server 2.4.48 and earlier, as well as various distributions such as Fedora (versions 34 and 35) and Debian (versions 9.0, 10.0, and 11.0).
Mitigation & Remediation
Organizations should upgrade to Apache HTTP Server 2.4.49 or later to mitigate this vulnerability. For those unable to upgrade, implementing strict input validation mechanisms and monitoring for unusual activities may provide some level of protection.
For more details on secure coding practices to prevent vulnerabilities, organizations should refer to the secure coding practices guide.
Detection Guidance
Organizations should monitor logs for any anomalies or unusual patterns related to the HTTP server's operations. Additionally, implementing network signatures to detect potential exploit attempts can enhance security measures.
AppSecure Threat Intelligence Insight
CVE-2021-39275 represents a critical concern for organizations utilizing Apache HTTP Server. The vulnerability highlights the importance of conducting regular security assessments and ensuring that systems are up-to-date with the latest patches.
This incident serves as a reminder of the evolving threat landscape and the necessity for proactive security measures. Organizations should consider implementing a vulnerability management program to identify and address vulnerabilities in a timely manner.
Additionally, organizations should consider engaging in penetration testing to validate their security posture and ensure that they are resilient against potential exploitation attempts.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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