Kyverno's Improper JMESPath Variable Evaluation Leads to Denial of Service
- 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- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean?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 1.14.2
- 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: partial
Summary
Kyverno is a policy engine designed for cloud native platform engineering teams. In versions 1.14.1 and below, a Denial of Service (DoS) vulnerability exists due to improper handling of JMESPath variable substitutions. Attackers with permissions to create or update Kyverno policies can craft expressions using the {{@}} variable combined with a pipe and an invalid JMESPath function (e.g., {{@ | non_existent_function }}). This leads to a nil value being substituted into the policy structure. Subsequent processing by internal functions, specifically getValueAsStringMap, which expect string values, results in a panic due to a type assertion failure (interface {} is nil, not string). This crashes Kyverno worker threads in the admission controller and causes continuous crashes of the reports controller pod. This is fixed in version 1.14.2.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: poc · Automatable: no · Technical impact: partial
- Record last updated
Affected versions
- kyverno kyverno
fixed in 1.14.2
- github.com/kyverno/kyvernoGo
fixed in 1.14.2