CVE-2025-55668: Medium Vulnerability in Apache Tomcat

This vulnerability allows an attacker to exploit session fixation in Apache Tomcat via the rewrite valve. With a CVSS score of 6.5, this medium-severity issue has been identified in versions of Tomcat from 11.0.0-M1 to 11.0.7, from 10.1.0-M1 to 10.1.41, and from 9.0.0.M1 to 9.0.105. Older, end-of-life versions may also be affected.

Risk to organizations includes potential unauthorized access to sensitive information due to session fixation, which can lead to session hijacking. As such, organizations should prioritize patching immediately.

The vulnerability was published on August 13, 2025, and is currently known to have an exploit available. Users are recommended to upgrade to version 11.0.8, 10.1.42, or 9.0.106 to mitigate this vulnerability.

Organizations should assess their exposure and apply the necessary patches to maintain the security of their systems.

Vulnerability Details

The official description of the vulnerability states: 'Session Fixation vulnerability in Apache Tomcat via rewrite valve. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.7, from 10.1.0-M1 through 10.1.41, from 9.0.0.M1 through 9.0.105. Older, EOL versions may also be affected.'

The CVSS score of 6.5 indicates a medium severity level, which suggests that while the vulnerability can be exploited, it may require some effort to do so successfully. The affected product is Apache Tomcat, and the relevant CWE classification for this vulnerability is CWE-384.

Organizations should schedule remediation to ensure they are not vulnerable to exploitation.

Technical Analysis

The root cause of this vulnerability lies in the way session fixation is handled by the rewrite valve in Apache Tomcat. The attack vector is network-based, allowing remote attackers to exploit the vulnerability.

The attack complexity is low, as no special privileges are required to exploit this vulnerability, but user interaction is needed to trigger the attack.

The confidentiality impact is high as it may lead to unauthorized access to user sessions. There is no integrity or availability impact associated with this vulnerability.

Risk & Impact Analysis

Real-world deployment of this vulnerability poses a significant risk to organizations using affected versions of Apache Tomcat. The potential for session hijacking can lead to unauthorized access to sensitive data, leading to data breaches and compliance risks.

The blast radius could be substantial, especially for organizations with extensive user interactions through their web applications, as compromised sessions could lead to widespread data leakage.

Organizations should address this vulnerability in their priority patch cycle to mitigate risks effectively.

Exploitation Status

Affected Versions

The affected versions include Apache Tomcat from 11.0.0-M1 through 11.0.7, from 10.1.0-M1 through 10.1.41, and from 9.0.0.M1 through 9.0.105. All versions prior to the vendor patch are vulnerable.

Mitigation & Remediation

Organizations should upgrade to Apache Tomcat version 11.0.8, 10.1.42, or 9.0.106 to mitigate this vulnerability. If immediate patching is not possible, consider implementing workarounds, such as avoiding the use of the rewrite valve for sensitive applications.

Additionally, organizations should review their configurations and perform a thorough security assessment to ensure no similar vulnerabilities exist.

For comprehensive support, organizations can engage in penetration testing to validate their security posture.

Detection Guidance

Monitor application logs for unusual session behaviors and track any unauthorized session creations. It is also advisable to implement rate limiting and other protective measures to prevent exploitation.

AppSecure Threat Intelligence Insight

The long-term significance of CVE-2025-55668 lies in its representation of session fixation vulnerabilities that can be exploited through established web technologies. This incident serves as a reminder of the importance of secure session management practices.

Security teams should take this opportunity to review their session handling mechanisms and ensure they are robust against similar vulnerabilities. Engaging in continuous security testing can help identify weaknesses before they are exploited.

For further insights on improving security measures, organizations can refer to our penetration testing methodology and the importance of establishing a solid security framework.

Organizations are encouraged to stay informed about vulnerabilities and trends in the security landscape to adapt their defenses accordingly.