CVE-2021-30640: Medium Vulnerability in Apache Tomcat

CVE-2021-30640 is a medium-severity vulnerability in the JNDI Realm of Apache Tomcat. This vulnerability allows an attacker to authenticate using variations of a valid user name and/or to bypass some of the protection provided by the LockOut Realm. The issue affects several versions of Apache Tomcat, specifically from 10.0.0-M1 to 10.0.5, 9.0.0.M1 to 9.0.45, and 8.5.0 to 8.5.65.

The severity of this vulnerability is classified as medium, with a CVSS score of 6.5. This indicates that while it is not critical, it poses a significant risk to organizations running the affected software. Exploitation of this vulnerability could allow unauthorized access and potential data leakage.

As of now, there are no known exploits for this vulnerability in the wild, but organizations should remain vigilant. Given the nature of the vulnerability, attackers may leverage it to gain unauthorized access to sensitive systems.

Organizations should prioritize patching immediately to prevent unauthorized access and mitigate potential risks associated with this vulnerability.

Vulnerability Details

The official description of CVE-2021-30640 states that it allows for authentication using variations of valid usernames. The vulnerability type is classified as privilege escalation, as it enables unauthorized authentication. The CVSS score is 6.5, indicating a medium severity level.

The affected products include Apache Tomcat versions 10.0.0-M1 to 10.0.5, 9.0.0.M1 to 9.0.45, and 8.5.0 to 8.5.65. The vulnerability was published on July 12, 2021, and is classified under CWE-116.

Technical Analysis

The root cause of this vulnerability lies in the JNDI Realm of Apache Tomcat, where it allows variations of valid usernames for authentication. The attack vector is network-based, requiring no user interaction, making it particularly dangerous. The attack complexity is considered high, as it may require specific knowledge of user account structures.

In terms of impact, the confidentiality of the system is at low risk, as it allows unauthorized access, while the integrity impact is high due to the potential for unauthorized actions performed by an attacker. The availability impact is noted as none.

Risk & Impact Analysis

The real-world deployment risk associated with CVE-2021-30640 is significant, especially for organizations utilizing Apache Tomcat in critical applications. If exploited, attackers could gain unauthorized access, leading to data breaches and potential regulatory repercussions.

The blast radius for this vulnerability is broad, impacting multiple versions of Tomcat across various deployments. Organizations must assess their exposure and prioritize patching based on the severity and potential impact of this vulnerability.

Given the CVSS score of 6.5 and lack of known exploits, organizations should address this vulnerability in their priority patch cycle to mitigate risks effectively.

Exploitation Status

Affected Versions

Affected versions include Apache Tomcat 10.0.0-M1 to 10.0.5, 9.0.0.M1 to 9.0.45, and 8.5.0 to 8.5.65. Organizations should ensure they are running a patched version of Tomcat to mitigate this vulnerability.

Mitigation & Remediation

Patching is the primary means of mitigating this vulnerability. Organizations should upgrade to the latest versions of Apache Tomcat or apply patches provided by their vendor. Additionally, implementing proper access controls and monitoring can help mitigate the risk of exploitation.

For further guidance on securing your applications, organizations may benefit from conducting regular penetration testing to identify potential vulnerabilities.

Detection Guidance

Organizations should monitor logs for any unusual authentication attempts, particularly those involving variations of valid usernames. Behavioral anomalies, such as unauthorized access to critical systems, should also be investigated.

AppSecure Threat Intelligence Insight

CVE-2021-30640 exemplifies the ongoing challenges in securing authentication mechanisms within widely used software. The low EPSS score of 0.00115 suggests a low probability of exploitation in the near term, but organizations must remain vigilant.

Security teams should consider this vulnerability as part of a broader strategy to enhance their application's security posture. Regular assessments and updates are critical to maintaining a secure environment.

For in-depth analysis and methodologies regarding vulnerability management, organizations can explore our resources on vulnerability management programs and the latest penetration testing methodologies to ensure comprehensive coverage.

Known Exploitation Timeline

This vulnerability is not currently listed in the KEV database, indicating that it is not actively exploited.

Affected Versions

Affected versions of Apache Tomcat include: 10.0.0-M1 to 10.0.5, 9.0.0.M1 to 9.0.45, and 8.5.0 to 8.5.65. Organizations should ensure they are using updated versions to protect against this vulnerability.

Mitigation & Remediation

To mitigate this vulnerability, organizations should apply the latest patches provided by Apache. Additionally, implementing strict access controls and conducting regular security assessments can help reduce the risk of exploitation.

For detailed guidance on securing your applications, organizations are encouraged to utilize our application security assessment services to identify and mitigate vulnerabilities effectively.