CVE-2023-3817

/// Technical description

Issue summary: Checking excessively long DH keys or parameters may be very slow.

Impact summary: Applications that use the functions DH_check(), DH_check_ex()

or EVP_PKEY_param_check() to check a DH key or DH parameters may experience long

delays. Where the key or parameters that are being checked have been obtained

from an untrusted source this may lead to a Denial of Service.

The function DH_check() performs various checks on DH parameters. After fixing

CVE-2023-3446 it was discovered that a large q parameter value can also trigger

an overly long computation during some of these checks. A correct q value,

if present, cannot be larger than the modulus p parameter, thus it is

unnecessary to perform these checks if q is larger than p.

An application that calls DH_check() and supplies a key or parameters obtained

from an untrusted source could be vulnerable to a Denial of Service attack.

The function DH_check() is itself called by a number of other OpenSSL functions.

An application c

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References