This vulnerability allows insufficient escaping of user-supplied data in mod_ssl in Apache HTTP Server 2.4.63 and earlier, enabling untrusted SSL/TLS clients to insert escape characters into log files in some configurations. In instances where CustomLog is used to log variables provided by mod_ssl, such as SSL_TLS_SNI, unsanitized data may appear in log files due to a lack of escaping by mod_log_config or mod_ssl.
The severity level of this vulnerability is classified as high, with a CVSS score of 7.5. This rating indicates a significant risk to organizations, particularly in configurations that rely on logging sensitive information from SSL/TLS connections. The potential for exposing sensitive data through log files necessitates immediate attention.
Currently, there is no known public exploit for this vulnerability, but the exploitability is high. Organizations utilizing affected versions should understand the urgency of addressing this issue to mitigate risks associated with data exposure.
Organizations should prioritize patching immediately.
Vulnerability Details
The official description of this vulnerability highlights the insufficient escaping of user-supplied data, which can lead to the insertion of escape characters in log files. This is particularly concerning when logging configurations involve CustomLog with specific variable formats. The affected product is the Apache HTTP Server, specifically versions 2.4.63 and earlier.
The CVSS score of 7.5 indicates a high severity level, with the following characteristics: low attack complexity and no privileges required for exploitation. The vulnerability falls under CWE-150, which relates to improper handling of user-supplied data.
Technical Analysis
The root cause of this vulnerability is the lack of proper escaping mechanisms in mod_ssl for user-supplied data. The attack vector is through the network, allowing an untrusted client to manipulate log entries. The attack complexity is low, with no user interaction required and no privileges necessary for exploitation.
The potential impact on confidentiality is high, as sensitive information can be logged without sanitization. Integrity and availability impacts are minimal in this context.
Risk & Impact Analysis
The deployment of Apache HTTP Server in various environments increases the risk associated with this vulnerability. Organizations should assess their logging configurations to ensure that sensitive data is not exposed through logs. The potential blast radius extends to any application utilizing Apache HTTP Server for handling SSL/TLS connections.
Given the high severity rating, organizations should address this vulnerability in their priority patch cycle. The urgency is emphasized by the potential for sensitive data exposure, which can lead to further security incidents.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
This vulnerability affects all versions of Apache HTTP Server prior to 2.4.64, specifically starting from 2.4.0 up to, but not including, 2.4.64.
Mitigation & Remediation
Organizations should upgrade to Apache HTTP Server version 2.4.64 or later to remediate this vulnerability. If patching is not immediately possible, consider implementing workarounds such as modifying logging configurations to prevent logging of unsanitized user data.
Additionally, organizations may enhance security through configuration hardening and network controls. Monitoring logs for anomalies can further aid in identifying potential misuse.
Penetration testing can also validate the effectiveness of applied remediation.
Detection Guidance
Security teams should monitor log files for the presence of escape characters or unusual patterns that may indicate exploitation attempts. Behavioral anomalies in SSL/TLS client interactions may also serve as indicators of compromise.
AppSecure Threat Intelligence Insight
The long-term significance of this vulnerability lies in its potential to expose sensitive data. Organizations should learn from this incident to enhance their security posture against similar vulnerabilities.
Security teams should remain vigilant in monitoring for trends in untrusted client interactions and consider implementing robust logging practices that sanitize user inputs. Ensuring that logging configurations do not expose sensitive data will significantly mitigate risks.
Understanding penetration testing methodologies can further enhance awareness and preparedness against such vulnerabilities.
Designing a robust vulnerability management program is essential for identifying and addressing vulnerabilities effectively.
Cloud penetration testing can also be a valuable component in assessing the security of applications using Apache HTTP Server.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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