h2o up to 2.3.0-beta2 X.509 Certificate signature verification

Summaryinfo

A vulnerability categorized as problematic has been discovered in h2o up to 2.3.0-beta2. Impacted is an unknown function of the component X.509 Certificate Handler. The manipulation results in signature verification. This vulnerability is identified as CVE-2023-41337. The attack can only be performed from the local network. There is not any exploit available. A patch should be applied to remediate this issue.

Detailsinfo

A vulnerability classified as problematic has been found in h2o up to 2.3.0-beta2. Affected is an unknown functionality of the component X.509 Certificate Handler. The manipulation with an unknown input leads to a signature verification vulnerability. CWE is classifying the issue as CWE-347. The product does not verify, or incorrectly verifies, the cryptographic signature for data. This is going to have an impact on integrity. CVE summarizes:

h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. In version 2.3.0-beta2 and prior, when h2o is configured to listen to multiple addresses or ports with each of them using different backend servers managed by multiple entities, a malicious backend entity that also has the opportunity to observe or inject packets exchanged between the client and h2o may misdirect HTTPS requests going to other backends and observe the contents of that HTTPS request being sent. The attack involves a victim client trying to resume a TLS connection and an attacker redirecting the packets to a different address or port than that intended by the client. The attacker must already have been configured by the administrator of h2o to act as a backend to one of the addresses or ports that the h2o instance listens to. Session IDs and tickets generated by h2o are not bound to information specific to the server address, port, or the X.509 certificate, and therefore it is possible for an attacker to force the victim connection to wrongfully resume against a different server address or port on which the same h2o instance is listening. Once a TLS session is misdirected to resume to a server address / port that is configured to use an attacker-controlled server as the backend, depending on the configuration, HTTPS requests from the victim client may be forwarded to the attacker's server. An H2O instance is vulnerable to this attack only if the instance is configured to listen to different addresses or ports using the listen directive at the host level and the instance is configured to connect to backend servers managed by multiple entities. A patch is available at commit 35760540337a47e5150da0f4a66a609fad2ef0ab. As a workaround, one may stop using using host-level listen directives in favor of global-level ones.

The weakness was released 12/12/2023 as GHSA-5v5r-rghf-rm6q. The advisory is available at github.com. This vulnerability is traded as CVE-2023-41337 since 08/28/2023. Successful exploitation requires user interaction by the victim. The technical details are unknown and an exploit is not available.

Applying the patch 35760540337a47e5150da0f4a66a609fad2ef0ab is able to eliminate this problem. The bugfix is ready for download at github.com.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Name

• h2o

Version

• 2.3.0-beta1
• 2.3.0-beta2

License

• open-source

Website

• Product: https://github.com/h2o/h2o/

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If you want to get best quality of vulnerability data, you may have to visit VulDB.

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