Gregor Samsa: Exploiting Java's XML Signature Verification

Summary: Google Project Zero researcher Felix Wilhelm found CVE-2022-34169, an integer truncation bug in a custom JIT compiler inside Java's standard library that processes untrusted XSLT programs during XML signature verification, leading to arbitrary code execution in many Java-based web applications and identity providers supporting SAML single sign-on. OpenJDK fixed the issue in July 2022 and the Apache BCEL project used by Xalan-J, the origin of the vulnerable code, released a patch in September 2022.
Bottom line: SAML remains the de-facto standard for large enterprises, and verifying a signature forces the application to run attacker-controlled XSLT transforms on attacker-controlled input, so the identity provider path that grants access to your SaaS estate carries a code-execution surface that a patched CVE does not close.

Read the original at Google Project Zero ↗

Topics: Vulnerabilities & Patching
Mentions: CVE-2022-34169
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