A security vulnerability has been detected in Cesanta Mongoose up to 7.20. This issue affects the function mg_aes_gcm_decrypt of the file /src/tls_aes128.c of the component GCM Authentication Tag Handler. Such manipulation leads to improper verification of cryptographic signature. The attack may be performed from remote. A high complexity level is associated with this attack. The exploitability is assessed as difficult. The exploit has been disclosed publicly and may be used. Upgrading to version 7.21 is capable of addressing this issue. It is advisable to upgrade the affected component. VulDB has contacted the vendor early and they confirmed quickly, that this issue got fixed already.
Vulnerability Details
This vulnerability allows improper verification of cryptographic signatures within the Cesanta Mongoose software. The CVSS score for this vulnerability is 6.3, indicating a medium severity level. The affected component is the GCM Authentication Tag Handler, specifically the mg_aes_gcm_decrypt function. This vulnerability was published on April 25, 2026, and is classified under CWE-345 and CWE-347.
Technical Analysis
The root cause of this vulnerability stems from the improper handling of cryptographic authentication tags. The attack vector is network-based, requiring no privileges or user interaction to exploit. The attack complexity is high, making successful exploitation difficult. The integrity impact is low, with no confidentiality or availability impact noted.
Risk & Impact Analysis
Risk to organizations includes potential unauthorized access and manipulation of cryptographic data. The blast radius can be significant, particularly for systems relying on secure communications. Given the medium CVSS score and the absence of known exploitation in the wild, organizations should address this vulnerability in their priority patch cycle.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
All versions prior to vendor patch 7.21 are affected by this vulnerability.
Mitigation & Remediation
Organizations should prioritize patching immediately by upgrading to version 7.21 of Cesanta Mongoose. In addition, implementing configuration hardening and access controls can further protect against potential exploitation of similar vulnerabilities.Penetration testing can also be considered to validate the security posture.
Detection Guidance
Organizations should monitor logs for unusual access patterns and behavioral anomalies that may indicate exploitation attempts. Additionally, implementing network signatures can help detect potential attack vectors.
AppSecure Threat Intelligence Insight
The long-term significance of this vulnerability lies in its potential to affect the integrity of cryptographic processes in applications. Security teams should learn from this incident to reinforce cryptographic practices and ensure timely updates to third-party components.Penetration testing methodology can provide insights into validating security controls. Furthermore, organizations should adopt a proactive approach in vulnerability management, continuously assessing and updating their defenses against evolving threats.Vulnerability management program design is essential for maintaining a robust security posture.API penetration testing can specifically help identify issues within API implementations.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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