A vulnerability in the HTML Cascading Style Sheets (CSS) module of ClamAV could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper error handling when splitting UTF-8 strings. An attacker could exploit this vulnerability by submitting a crafted HTML file to be scanned by ClamAV on an affected device. A successful exploit could allow the attacker to terminate the scanning process.
The CVSS score for this vulnerability is 5.3, indicating a medium severity. The risk to organizations includes potential service interruptions and decreased availability of affected systems. Given the nature of the vulnerability, organizations should address it in their priority patch cycle.
As of the latest intelligence, there is no public exploit confirmed, and the vulnerability is currently categorized as awaiting analysis. Organizations are advised to monitor their systems and be prepared to apply any updates or patches provided by the vendor.
Urgency for defenders remains moderate, and efforts should be undertaken to validate the effectiveness of any remediation measures taken.
Vulnerability Details
The vulnerability allows for a denial of service condition on devices running ClamAV as a result of improper error handling in the CSS module. The CVSS vector for this vulnerability is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L, indicating a network attack vector with low complexity, requiring no privileges or user interaction.
Affected products are currently unspecified, but mitigation steps should be taken to ensure that systems are not vulnerable to this type of attack.
Technical Analysis
The root cause of this vulnerability lies in the improper handling of errors associated with UTF-8 string processing within the CSS module of ClamAV. Attackers may leverage this flaw by submitting specially crafted HTML files, which when processed, could lead to the termination of the scanning process.
The attack vector is network-based, and the attack complexity is low. Importantly, no privileges are required for exploitation, and user interaction is not necessary. The impact on availability is classified as low, while confidentiality and integrity impacts are none.
Risk & Impact Analysis
Risk to organizations includes potential interruptions in service due to the denial of service condition. The blast radius could extend to all instances of ClamAV deployed in environments where this vulnerability is present. Organizations should be aware of the potential for service outages, especially in environments reliant on ClamAV for malware detection.
With a CVSS score of 5.3, organizations should prioritize addressing this vulnerability within their patch cycles. The relatively low EPS score of 0.00041 indicates a lower likelihood of exploitation, but organizations should not become complacent.
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
Currently, specific versions of ClamAV affected by this vulnerability are unspecified. Organizations should assume that all versions prior to any forthcoming vendor patch are potentially vulnerable.
Mitigation & Remediation
To mitigate this vulnerability, organizations should monitor for any updates or patches from ClamAV. Upon release, they should apply the recommended updates immediately. In the absence of a patch, organizations may implement network controls to restrict the types of files being scanned. Additionally, regular reviews of scanning logs can help identify any unusual activity.
Organizations can also benefit from adopting a robust penetration testing program to identify and remediate vulnerabilities proactively.
Detection Guidance
Organizations should monitor logs for any signs of unusual activity related to the scanning processes of ClamAV. Behavioral anomalies during file scanning that lead to unexpected terminations should be investigated immediately. Additionally, implementing network signatures that detect exploitation attempts may provide early warnings.
AppSecure Threat Intelligence Insight
This vulnerability highlights the importance of secure coding practices, particularly in the handling of user input and error conditions. Organizations should review their software development lifecycle to ensure that similar vulnerabilities are not introduced in future releases.
Security teams should also consider the insights gained from this incident as part of their vulnerability management program, ensuring that they develop strategies that prioritize the identification and remediation of similar vulnerabilities.
In conclusion, organizations are reminded to stay vigilant and proactive in their security measures to protect against potential exploitation, especially given the rapidly evolving threat landscape.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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