OPA Compiler: Bypass of WithUnsafeBuiltins using `with` keyword to mock functions
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 0.43.1, 0.44.0
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: poc
- Automatable: no
- Technical impact: total
Summary
Open Policy Agent (OPA) is an open source, general-purpose policy engine. The Rego compiler provides a (deprecated) `WithUnsafeBuiltins` function, which allows users to provide a set of built-in functions that should be deemed unsafe — and as such rejected — by the compiler if encountered in the policy compilation stage. A bypass of this protection has been found, where the use of the `with` keyword to mock such a built-in function (a feature introduced in OPA v0.40.0), isn’t taken into account by `WithUnsafeBuiltins`. Multiple conditions need to be met in order to create an adverse effect. Version 0.43.1 contains a patch for this issue. As a workaround, avoid using the `WithUnsafeBuiltins` function and use the `capabilities` feature instead.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: poc · Automatable: no · Technical impact: total
- Record last updated
Affected versions
- open-policy-agent opa
From 0.40.0 · fixed in 0.43.1
- github.com/open-policy-agent/opaGo
From 0.40.0 · fixed in 0.44.0
- github.com/open-policy-agent/opaGo
From 0.40.0 · fixed in 0.43.1