Vulnerability · Published Feb 9, 2022 · Assigned by GitHub_M

CVE-2022-23628Array literal misordering in github.com/open-policy-agent/opa

Medium 6.3

In plain English

A medium-severity security flaw in opa from open-policy-agent. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 1.0% (higher than 64% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.3Medium
Exploit odds (30 days)1.0%top 36.2% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official description

OPA is an open source, general-purpose policy engine. Under certain conditions, pretty-printing an abstract syntax tree (AST) that contains synthetic nodes could change the logic of some statements by reordering array literals. Example of policies impacted are those that parse and compare web paths. **All of these** three conditions have to be met to create an adverse effect: 1. An AST of Rego had to be **created programmatically** such that it ends up containing terms without a location (such as wildcard variables). 2. The AST had to be **pretty-printed** using the `github.com/open-policy-agent/opa/format` package. 3. The result of the pretty-printing had to be **parsed and evaluated again** via an OPA instance using the bundles, or the Golang packages. If any of these three conditions are not met, you are not affected. Notably, all three would be true if using **optimized bundles**, i.e. bundles created with `opa build -O=1` or higher. In that case, the optimizer would fulfil condition (1.), the result of that would be pretty-printed when writing the bundle to disk, fulfilling (2.). When the bundle was then used, we'd satisfy (3.). As a workaround users may disable optimization when creating bundles.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Gogithub.com/open-policy-agent/opa0.37.2GHSA-hcw3-j74m-qc58
Gogithub.com/open-policy-agent/opa0.37.2GO-2022-0316

Affected products (as reported)

VendorProductVersions
open-policy-agent opa >= 0.33.1, < 0.37.0

Weakness: CWE-682 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L

References