Tekton Pipelines versions starting from 1.0.0 up to but not including 1.0.2, 1.3.4, 1.6.2, 1.9.3, and 1.11.1 contain a vulnerability (CWE-88) where the git resolver's revision parameter is passed directly as a positional argument to git fetch without validation against leading '-' characters. This allows injection of arbitrary git fetch flags, such as --upload-pack, potentially leading to execution of arbitrary binaries on the resolver pod. The validateRepoURL function permits URLs beginning with '/', enabling attackers who can submit ResolutionRequest objects to chain these behaviors for code execution. Since the tekton-pipelines-resolvers ServiceAccount has cluster-wide permissions to get/list/watch all Secrets, exploitation results in full cluster-wide secret exfiltration. Fixed versions include 1.0.2, 1.3.4, 1.6.2, 1.9.3, and 1.11.1.

Successful exploitation allows an attacker with permission to submit ResolutionRequest objects to execute arbitrary code on the resolver pod. Given the resolver pod's ServiceAccount has cluster-wide read access to all Kubernetes Secrets, this leads to full cluster-wide secret exfiltration. The vulnerability impacts confidentiality, integrity, and availability of the cluster environment.

Fixed versions 1.0.2, 1.3.4, 1.6.2, 1.9.3, and 1.11.1 address this vulnerability. It is recommended to upgrade affected Tekton Pipelines installations to one of these versions. No vendor advisory explicitly states alternative mitigations or that no action is required. Patch status is confirmed by vendor advisories linked from Red Hat. Users should apply the official fixes promptly.