Headline
GHSA-xrqc-7xgx-c9vh: RCE via ZipSlip and symbolic links in argoproj/argo-workflows
Summary
The patch deployed against CVE-2025-62156 is ineffective against malicious archives containing symbolic links.
Details
The untar code that handles symbolic links in archives is unsafe. Concretely, the computation of the link’s target and the subsequent check are flawed: https://github.com/argoproj/argo-workflows/blob/5291e0b01f94ba864f96f795bb500f2cfc5ad799/workflow/executor/executor.go#L1034-L1037
PoC
- Create a malicious archive containing two files: a symbolik link with path “./work/foo” and target "/etc", and a normal text file with path "./work/foo/hostname".
- Deploy a workflow like the one in https://github.com/argoproj/argo-workflows/security/advisories/GHSA-p84v-gxvw-73pf with the malicious archive mounted at /work/tmp.
- Submit the workflow and wait for its execution.
- Connect to the corresponding pod and observe that the file “/etc/hostname” was altered by the untar operation performed on the malicious archive. The attacker can hence alter arbitrary files in this way.
Impact
The attacker can overwrite the file /var/run/argo/argoexec with a script of their choice, which will be executed at the pod’s start.
Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.