In Apache HTTP Server 2.4.53 and earlier, a malicious request to a lua script that calls r:parsebody(0) may cause a denial of service due to no default limit on possible input size. This vulnerability is classified as high severity with a CVSS score of 7.5, indicating a significant risk to organizations relying on this software.
Risk to organizations includes potential downtime and service disruption, which can lead to loss of business and damage to reputation. Given the low attack complexity and the lack of required privileges or user interaction, the vulnerability can be exploited easily by attackers.
Currently, there are no known exploits in the wild, and the vulnerability is not listed in the Known Exploited Vulnerabilities (KEV) catalog. However, this does not diminish its potential impact, and organizations should prioritize patching immediately.
As a precaution, organizations must assess their systems for affected versions and implement necessary remediation to mitigate the risk associated with this vulnerability.
Vulnerability Details
The vulnerability description states that in Apache HTTP Server 2.4.53 and earlier, a malicious request to a lua script that calls r:parsebody(0) may cause a denial of service due to no default limit on possible input size. This leads to an availability impact classified as high.
The CVSS score for this vulnerability is 7.5, indicating high severity. The vulnerability is categorized under CWE-770, which pertains to "Allocation of Resources Without Limits or Throttling."
Published on June 9, 2022, the vulnerability affects Apache HTTP Server and components associated with Fedora versions 35 and 36, as well as NetApp's clustered_data_ontap.
Technical Analysis
The root cause of this vulnerability stems from the lack of input size limits in the lua script processing within Apache HTTP Server. This results in a denial of service when a crafted request is sent.
The attack vector is network-based, requiring no privileges or user interaction to exploit. The attack complexity is low, making it accessible for attackers to leverage this vulnerability.
The impact on availability is significant, as successful exploitation could lead to service outages, affecting all users and systems relying on the affected Apache HTTP Server.
Risk & Impact Analysis
Deployments that utilize Apache HTTP Server 2.4.53 or earlier are at considerable risk. The absence of input size limits can lead to significant service disruptions, particularly for organizations that rely heavily on web services for business operations.
The blast radius for this vulnerability can be extensive, as it affects multiple versions of Apache and products built on it. Organizations should assess their exposure and prioritize remediation based on their specific risk profile.
Given the high CVSS score and the potential for service outages, organizations should address this vulnerability in their priority patch cycle.
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The vulnerability affects Apache HTTP Server versions 2.4.53 and earlier. Additionally, it impacts Fedora versions 35 and 36, as well as NetApp's clustered_data_ontap component.
Mitigation & Remediation
Organizations should update their Apache HTTP Server to the latest version to mitigate this vulnerability. If a patch is unavailable, consider implementing workarounds such as limiting input size through configuration changes.
For ongoing protection, organizations should engage in regular security assessments, which can be facilitated through penetration testing to identify vulnerabilities in their systems.
Detection Guidance
Monitoring logs for abnormal requests to lua scripts and tracking system performance metrics can help in early detection of potential exploitation attempts.
Behavioral anomalies in server response times or unexpected service outages could indicate exploitation.
AppSecure Threat Intelligence Insight
This vulnerability represents a significant risk for organizations using Apache HTTP Server, emphasizing the importance of input validation and resource management in web applications.
Security teams should take this incident as a lesson to reinforce practices around securing web applications, especially those exposing lua scripts.
Organizations are encouraged to adopt proactive security measures, including regular updates and security assessments, which can be explored in our vulnerability management program to enhance their overall security posture.
Additionally, teams should familiarize themselves with best practices for security testing, which can be found in our penetration testing methodology guide.
The need for continuous security oversight cannot be overstated, ensuring that vulnerabilities are identified and mitigated promptly.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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