A weakness has been identified in Cesanta Mongoose up to version 7.20. This vulnerability allows manipulation of the argument optlen in the function handle_opt of the file /src/net_builtin.c within the TCP Option Handler component. This manipulation can lead to an infinite loop, which can be exploited remotely. The exploit has been made available to the public and could be used for attacks. Upgrading to version 7.21 effectively resolves this issue, and upgrading the affected component is strongly advised.
The severity of this vulnerability is classified as medium, with a CVSS score of 5.5. This classification indicates that while the vulnerability does not pose an immediate critical risk, it still requires attention due to the potential for remote exploitation.
Risk to organizations includes potential service disruption due to the infinite loop, which could affect system availability. Attackers may leverage this vulnerability to conduct denial-of-service attacks, making it crucial for organizations to address this vulnerability promptly.
Organizations should prioritize patching immediately. The vendor has confirmed that the issue has been fixed, thus highlighting the importance of staying updated with the latest software versions.
Vulnerability Details
The official description states that a weakness has been identified in Cesanta Mongoose up to version 7.20. The vulnerability affects the function handle_opt of the file /src/net_builtin.c of the component TCP Option Handler. The attack vector is network-based with low complexity, requiring no privileges or user interaction. The vulnerability's impact is classified as low in terms of availability, as it can cause an infinite loop.
The CVSS score for this vulnerability is 5.5, indicating medium severity, and it is classified under CWE-404 and CWE-835.
Technical Analysis
The root cause of this vulnerability lies in the improper handling of TCP options within the Mongoose framework. The function handle_opt fails to validate the input length, allowing an attacker to craft a request that manipulates the optlen argument, leading to an infinite loop.
The attack vector for this vulnerability is network-based, meaning an attacker does not need physical access to exploit it. The attack complexity is low, and no privileges or user interaction are required. The availability impact is low, as the infinite loop can disrupt service without compromising confidentiality or integrity.
Risk & Impact Analysis
Real-world deployment risk includes potential service outages and denial-of-service attacks against systems using affected versions of Mongoose. The blast radius could vary based on the deployment scale, but any organization using this framework is potentially at risk.
Organizations should address this vulnerability in their priority patch cycle. Regular software updates and vulnerability management practices are essential to mitigate threats from known vulnerabilities.
Signal | Status |
|---|---|
Known Exploit | Yes |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
All versions prior to vendor patch (7.21) are affected. Organizations using Cesanta Mongoose should upgrade to this version to mitigate the identified vulnerability.
Mitigation & Remediation
Organizations should apply the latest patches from the vendor to resolve this vulnerability. Upgrading to version 7.21 is essential. If immediate patching is not feasible, consider implementing network controls to limit access to vulnerable systems.
For further security assurance, organizations can benefit from penetration testing to identify and rectify similar weaknesses.
Detection Guidance
To detect potential exploitation of this vulnerability, organizations should monitor logs for unusual network traffic patterns, especially requests targeting TCP options. Behavioral anomalies such as service unavailability or increased resource consumption should also be flagged for further investigation.
AppSecure Threat Intelligence Insight
This vulnerability represents a notable risk within the Cesanta Mongoose framework, emphasizing the importance of regular updates and vulnerability management. The trend towards network-exploitable vulnerabilities requires security teams to adopt proactive measures.
Security teams should remain vigilant and consider integrating continuous security practices, such as continuous penetration testing, to identify vulnerabilities promptly.
Furthermore, organizations should establish a robust application security assessment process to continuously evaluate and strengthen their security posture.
Finally, organizations should remain engaged with cybersecurity communities to stay informed about emerging threats and effective countermeasures, ensuring they can respond swiftly to vulnerabilities like CVE-2026-6985.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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