cURL up to 8.9.1 OCSP Stapling certificate validation

Summaryinfo

A vulnerability was found in cURL up to 8.9.1. It has been classified as critical. The impacted element is an unknown function of the component OCSP Stapling Handler. The manipulation leads to certificate validation. This vulnerability is listed as CVE-2024-8096. The attack may be initiated remotely. There is no available exploit. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in cURL up to 8.9.1. It has been rated as problematic. This issue affects an unknown code block of the component OCSP Stapling Handler. The manipulation with an unknown input leads to a certificate validation vulnerability. Using CWE to declare the problem leads to CWE-295. The product does not validate, or incorrectly validates, a certificate. Impacted is integrity. The summary by CVE is:

When curl is told to use the Certificate Status Request TLS extension, often referred to as OCSP stapling, to verify that the server certificate is valid, it might fail to detect some OCSP problems and instead wrongly consider the response as fine. If the returned status reports another error than 'revoked' (like for example 'unauthorized') it is not treated as a bad certficate.

The weakness was presented by Daniel Stenberg. It is possible to read the advisory at curl.se. The identification of this vulnerability is CVE-2024-8096 since 08/22/2024. The exploitation is known to be difficult. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. The technical details are unknown and an exploit is not publicly available. The attack technique deployed by this issue is T1587.003 according to MITRE ATT&CK.

The vulnerability scanner Nessus provides a plugin with the ID 207713 (Nessus Network Monitor < 6.5.0 Multiple Vulnerabilities (TNS-2024-17)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 8.10.0 eliminates this vulnerability. The upgrade is hosted for download at curl.se. Applying the patch aeb1a281cab13c7ba is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (207713). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

• Network Utility Software

Name

• cURL

Version

• 8.9.0
• 8.9.1

License

• open-source

Website

• Product: https://github.com/curl/curl/

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Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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