Kyverno's Improper JMESPath Variable Evaluation Leads to Denial of Service
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.7epss 0.5%
exploitation probability
0.5%top 59% of all CVEs
observed exploitation
nono source reports it
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.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
Affected products
kyverno · kyverno