Ubuntu: (Multiple Advisories) (CVE-2023-3817): OpenSSL vulnerabilities

Ubuntu: (Multiple Advisories) (CVE-2023-3817): OpenSSL vulnerabilities

Severity

5

CVSS

(AV:N/AC:L/Au:N/C:N/I:N/A:P)

Published

07/31/2023

Created

10/20/2023

Added

10/19/2023

Modified

01/30/2025

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 calling any of those other functions may similarly be affected. The other functions affected by this are DH_check_ex() and EVP_PKEY_param_check(). Also vulnerable are the OpenSSL dhparam and pkeyparam command line applications when using the "-check" option. The OpenSSL SSL/TLS implementation is not affected by this issue. The OpenSSL 3.0 and 3.1 FIPS providers are not affected by this issue.

Solution(s)

• ubuntu-pro-upgrade-libssl1-0-0
• ubuntu-pro-upgrade-libssl1-1
• ubuntu-pro-upgrade-libssl3
• ubuntu-pro-upgrade-openssl

References

• https://attackerkb.com/topics/cve-2023-3817
• CVE - 2023-3817
• USN-6435-1
• USN-6435-2
• USN-6450-1
• USN-6709-1