Description

Issue Summary: An error in the callback used to verify the certificate provided in a Root CA key update Certificate Management Protocol (CMP) message response rendered the certificate validation ineffectual, which could lead to escalation of credentials from the Registration Authority (RA) level to the root Certification Authority (root CA) level. Impact Summary: The Registration Autority could replace the root CA certificate for the CMP clients with an arbitrary root CA certificate. One of the parts of the Certificate Management Protocol (CMP), specified in RFC 9810, is Root Certification Authority (root CA) key Rollover, which is sent by the server in a message with type 'id-it-rootCaKeyUpdate'. As part of these messages, 'newWithOld' certificate, the new root CA certificate signed with the old root CA key, is provided, and verifying its signature is crucial for transferring the trust from the old CA key to the new one. The 'id-it-rootCaKeyUpdate' messages are expected to be processed with OSSL_CMP_get1_rootCaKeyUpdate(), that is expected to verify the 'newWithOld' certificate. A typo in the certificate chain building code led to adding an incorrect certificate ('newWithOld' instead of 'oldRoot') to the certificate chain, rendering the certificate verification process ineffectual (only the issuer name and the algorithm OIDs were verified by other parts of the verification code). An attacker who already has credentials that satisfy the CMP message protection checks can generate a new key pair and use a crafted self-signed certificate in its 'id-it-rootCaKeyUpdate' CMP messages which affected CMP clients would accept as a new trust anchor. Significant preconditions for the attack (having valid RA-level credentials) are the reason the issue was assigned Low severity. The FIPS modules are not affected by this issue, as the affected code is outside the OpenSSL FIPS module boundary.

Weaknesses 1

Affected Products 4

References 5

• github.com https://github.com/openssl/openssl/commit/54d0989997e5fc26057009a9782c3441ce3842fb
  Patch
• github.com https://github.com/openssl/openssl/commit/777b363b16fcf2153bb3ded39dc3838713667c44
  Patch
• github.com https://github.com/openssl/openssl/commit/d35cd473a271bf3ce7bf3d32af53217fb83ae92c
  Patch
• github.com https://github.com/openssl/openssl/commit/d531f21c0fe99067a66fc0ff1161ef127f9cd70b
  Patch
• openssl-library.org https://openssl-library.org/news/secadv/20260609.txt
  Vendor Advisory

Remediation

• github.com https://github.com/openssl/openssl/commit/54d0989997e5fc26057009a9782c3441ce3842fb
  Patch
• github.com https://github.com/openssl/openssl/commit/777b363b16fcf2153bb3ded39dc3838713667c44
  Patch
• github.com https://github.com/openssl/openssl/commit/d35cd473a271bf3ce7bf3d32af53217fb83ae92c
  Patch
• github.com https://github.com/openssl/openssl/commit/d531f21c0fe99067a66fc0ff1161ef127f9cd70b
  Patch