CVE-2023-49087
Validation of SignedInfo
描述
Validation of an XML Signature requires verification that the hash value of the related XML-document (after any optional transformations and/or normalizations) matches a specific DigestValue-value, but also that the cryptografic signature on the SignedInfo-tree (the one that contains the DigestValue) verifies and matches a trusted public key. Within the simpleSAMLphp/xml-security library (https://github.com/simplesamlphp/xml-security), the hash is being validated using SignedElementTrait::validateReference, and the signature is being verified in SignedElementTrait::verifyInternal https://github.com/simplesamlphp/xml-security/blob/master/src/XML/SignedElementTrait.php:  What stands out is that the signature is being calculated over the canonical version of the SignedInfo-tree. The validateReference method, however, uses the original non-canonicalized version of SignedInfo. ### Impact If an attacker somehow (i.e. by exploiting a bug in PHP's canonicalization function) manages to manipulate the canonicalized version's DigestValue, it would be potentially be possible to forge the signature. No possibilities to exploit this were found during the investigation.
如何修補 CVE-2023-49087
要修補 CVE-2023-49087,請將受影響套件升級到下列已修補版本。
- —升級至 5.0.0-alpha.13 或更新版本
- —升級至 1.6.12 或更新版本
CVE-2023-49087 正在被利用嗎?
低 — EPSS 為 0.2%,目前沒有觀察到大規模利用活動。
受影響套件(2)
- >= 5.0.0-alpha.12, < 5.0.0-alpha.13