CVE-2024-0853 is a medium-severity vulnerability affecting Haxx curl, specifically version 8.5.0. This vulnerability allows attackers to bypass SSL verification due to improper caching of SSL session IDs. The flaw arises when curl retains the SSL session ID for connections even if the online certificate status protocol (OCSP stapling) verification fails. As a result, if a subsequent transfer is made to the same hostname while the session ID cache is still fresh, the verify status check can be skipped, potentially leading to security bypass.
The CVSS score for this vulnerability is 5.3, indicating a medium severity level. This score signifies that while the vulnerability poses a risk, the potential impact and exploitability are not as critical as higher-severity vulnerabilities. Nonetheless, organizations utilizing the affected version of curl should be aware of the risks associated with this vulnerability.
Risk to organizations includes unauthorized access to sensitive data or systems due to the failure in SSL verification. Attackers may leverage this vulnerability to perform man-in-the-middle attacks, leading to data interception or manipulation. Organizations should prioritize patching immediately to mitigate these risks and prevent exploitation.
Currently, there are no known exploits or public proof-of-concept (PoC) for this vulnerability, indicating a lower immediate risk for exploitation in the wild. However, the nature of the vulnerability still requires attention and remediation.
Organizations should address this vulnerability during their patch cycle, as it is crucial for maintaining the security and integrity of their systems.
Vulnerability Details
The vulnerability is a result of curl retaining the SSL session ID for connections even when the OCSP stapling verification fails. The official description notes that a transfer to the same hostname could succeed if the session ID cache remains fresh, effectively skipping the necessary verify status check. This vulnerability has been classified under CWE-295, indicating an issue with improper certificate validation.
It is essential to note that the vulnerability was published on February 3, 2024, and has been modified since its initial disclosure. The CVSS 3.1 vector for this vulnerability is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N, which reflects its characteristics and potential impact.
This vulnerability affects curl version 8.5.0. Organizations should ensure they are running the patched version to avoid potential exploitation.
Technical Analysis
The root cause of CVE-2024-0853 stems from a flaw in the session ID caching mechanism employed by curl. When the OCSP stapling verification fails, curl should ideally invalidate the corresponding session ID to prevent any unauthorized reuse. However, due to improper handling, the session ID remains cached, allowing subsequent connections to bypass the necessary verification checks. The attack vector is network-based, meaning an attacker must be capable of intercepting traffic between the client and the server.
The vulnerability requires no privileges, meaning any user can exploit it without needing special access. Furthermore, it does not necessitate user interaction, which lowers the barrier for exploitation. The impacts on confidentiality are minimal, as no confidential data is exposed; however, the integrity impact is low due to the possibility of data manipulation.
Risk & Impact Analysis
Organizations using curl version 8.5.0 must recognize the potential risks associated with CVE-2024-0853. The ability to bypass SSL verification increases the likelihood of man-in-the-middle attacks, where an attacker could intercept and manipulate data in transit. The risk is particularly pertinent for organizations that rely heavily on secure communication for sensitive transactions or data exchanges.
Given the attack vector and required conditions, the potential blast radius for this vulnerability could extend to all users of the affected software. The urgency for remediation is classified as medium, and organizations should schedule remediation within their patch cycle to ensure ongoing security.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The affected version of curl is 8.5.0. Organizations should ensure they upgrade to the latest version that addresses this vulnerability to prevent potential exploitation. If version information is missing, it is advisable to state that all versions prior to the vendor patch are vulnerable.
Mitigation & Remediation
To mitigate the risks associated with CVE-2024-0853, organizations should apply the latest patches provided by Haxx for curl. Upgrading to a fixed version is critical to ensure the integrity of SSL communications. If a patch is unavailable, consider implementing workarounds such as disabling session ID caching or enforcing stricter validation checks.
For ongoing security, organizations may implement configuration hardening practices and network controls to limit exposure. Regular monitoring of logs for unusual activity can also help detect any potential exploitation attempts.
Penetration testing can further validate the effectiveness of these measures and identify any remaining vulnerabilities.
Detection Guidance
Organizations should monitor logs for indicators of exploitation, such as unusual SSL connection attempts or failures in OCSP verification. Behavioral anomalies in network traffic that suggest session ID reuse may also indicate potential abuse of this vulnerability.
In addition, tracking system changes related to curl updates and configurations can provide insights into whether appropriate security measures are being implemented.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2024-0853 lies in its illustration of the importance of robust SSL verification processes. As organizations increasingly rely on secure communications, vulnerabilities that allow bypassing these checks highlight the need for vigilant security practices. This case emphasizes the necessity for regular updates and proactive vulnerability management.
Security teams should consider this vulnerability as part of a broader trend in certificate validation issues, reinforcing the need for comprehensive security assessments. Lessons learned from this incident can guide organizations in reinforcing their SSL configurations and ensuring that all potential vulnerabilities are addressed.
Adopting best practices in penetration testing and vulnerability assessments can further bolster an organization’s defense against such vulnerabilities.
Implementing a comprehensive vulnerability management program is essential for adapting to emerging threats and maintaining the security posture of the organization.
API penetration testing should also be considered to assess the security of applications relying on SSL/TLS protocols.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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