CVE-2021-30641 affects Apache HTTP Server versions 2.4.39 to 2.4.46 and is classified as a medium-severity vulnerability. This vulnerability allows unexpected matching behavior when the 'MergeSlashes' directive is set to OFF. Organizations using affected versions should be aware of the implications of this flaw, as it can potentially lead to integrity impacts, albeit with no confidentiality or availability impacts.
The CVSS score for this vulnerability is 5.3, indicating a medium severity level. The attack vector is network-based, and the attack complexity is low, meaning that exploitation could be achievable without significant effort. Given these factors, organizations should prioritize addressing this vulnerability to prevent potential exploitation.
As of now, there are no public exploits confirmed, but the presence of a GitHub proof of concept indicates that attackers may leverage this vulnerability if it remains unpatched. Organizations should prioritize patching immediately to mitigate risks associated with this vulnerability.
Given that this vulnerability has been modified and may be subject to new findings, continuous monitoring and readiness to implement patches or mitigations is essential. The urgency for defenders to act on this vulnerability cannot be overstated.
Vulnerability Details
The vulnerability description states that Apache HTTP Server versions 2.4.39 through 2.4.46 exhibit unexpected matching behavior when the 'MergeSlashes' directive is set to OFF. This behavior can lead to potential integrity impacts, which is a concern for organizations relying on the stability and security of their web services.
The CVSS score of 5.3 reflects the medium severity of this vulnerability, with a low attack complexity and no privileges required for exploitation. This indicates that an unauthenticated attacker could potentially exploit the vulnerability without any user interaction. The vulnerability was published on June 10, 2021, and is classified under the NVD CWE as 'Other'.
Technical Analysis
The root cause of CVE-2021-30641 lies in the unexpected behavior of the Apache HTTP Server when handling requests under certain configurations. This misbehavior occurs specifically when the 'MergeSlashes' directive is set to OFF, leading to potential integrity issues.
The attack vector is network-based, allowing attackers to exploit this vulnerability remotely. The attack complexity is rated as low, meaning that minimal effort is required to exploit the vulnerability. No privileges are required for exploitation, and user interaction is not necessary.
The vulnerability primarily impacts the integrity of the data processed by the affected Apache HTTP Server instances, while confidentiality and availability are not impacted. Thus, the focus should be on ensuring data integrity during web service operations.
Risk & Impact Analysis
Risk to organizations includes potential integrity impacts that could disrupt web services relying on Apache HTTP Server versions 2.4.39 to 2.4.46. Given the low attack complexity, organizations may be at risk of exploitation if they do not act promptly to patch this vulnerability.
The medium CVSS score indicates that while not critical, this vulnerability poses significant risks that should not be overlooked. Organizations should address this vulnerability in their priority patch cycle to mitigate potential exploitation.
The EPSS score of 0.3636 places this vulnerability in the 97th percentile, suggesting a relatively high likelihood of exploitation compared to other vulnerabilities. This reinforces the need for organizations to prioritize remediation efforts.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | Yes |
Public PoC | Yes |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The affected versions of Apache HTTP Server are from 2.4.39 to 2.4.46. Additionally, other vulnerable components include Debian Linux versions 9.0 and 10.0, Fedora versions 34 and 35, and various Oracle products such as the Enterprise Manager Ops Center and Instantis EnterpriseTrack.
Mitigation & Remediation
Organizations should prioritize patching Apache HTTP Server to a version that is not vulnerable to CVE-2021-30641. Ensure that the latest updates are applied to all affected systems. If a patch is not yet available, consider disabling the 'MergeSlashes' feature as a temporary workaround until the patch can be applied.
For more information on effective remediation strategies, organizations can consult resources on penetration testing and security assessment best practices.
Detection Guidance
Organizations should monitor their logs for any unusual request patterns that may indicate exploitation attempts related to this vulnerability. Look for behavioral anomalies in web traffic, particularly involving URLs that could trigger the unexpected matching behavior in Apache HTTP Server.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2021-30641 highlights the necessity for organizations to maintain a proactive security posture. This vulnerability represents a broader trend in web server misconfigurations, emphasizing the importance of secure default settings.
Organizations should learn from this incident and consider implementing a comprehensive security framework that includes regular audits and assessments of their web applications and servers. Such measures can help detect similar vulnerabilities before they can be exploited.
For further reading on improving security practices, organizations are encouraged to explore topics such as vulnerability management programs and penetration testing methodologies to enhance their defenses.
Ultimately, organizations should strive for continuous improvement in their security strategies to effectively mitigate risks associated with vulnerabilities like CVE-2021-30641.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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