Skip to content

DoS through large directory app manifest files

Moderate
crenshaw-dev published GHSA-jhqp-vf4w-rpwq Jun 21, 2022

Package

gomod github.com/argoproj/argo-cd (Go)

Affected versions

0.7.0 through 2.1.15, 2.2.9, 2.3.4, 2.4.0

Patched versions

2.1.16, 2.2.10, 2.3.5, 2.4.1

Description

Impact

All versions of Argo CD starting with v0.7.0 are vulnerable to an uncontrolled memory consumption bug, allowing an authorized malicious user to crash the repo-server service. The repo-server is a critical component of Argo CD, so crashing the repo-server effectively denies core Argo CD services (such as syncing Application updates).

To achieve denial of service, the attacker must be an authenticated Argo CD user authorized to deploy Applications from a repository which contains (or can be made to contain) a large file.

Patches

A patch for this vulnerability has been released in the following Argo CD versions:

  • v2.4.1
  • v2.3.5
  • v2.2.10
  • v2.1.16

The patch introduces a new reposerver.max.combined.directory.manifests.size config parameter, which you should tune before upgrading in production. It caps the maximum total file size of .yaml/.yml/.json files in directory-type (raw manifest) Applications. The default max is 10M per Application. This max is designed to keep any single app from consuming more than 3G of memory in the repo-server (manifests consume more space in memory than on disk). The 300x ratio assumes a maliciously-crafted manifest file. If you only want to protect against accidental excessive memory use, it is probably safe to use a smaller ratio.

If your organization uses directory-type Applications with very many manifests or very large manifests then check the size of those manifests and tune the config parameter before deploying this change to production. When testing, make sure to do a "hard refresh" in either the CLI or UI to test your directory-type App. That will make sure you're using the new max logic instead of relying on cached manifest responses from Redis.

Workarounds

There is no workaround besides upgrading.

To mitigate the issue, carefully limit 1) who can configure repos (determined by RBAC), 2) which repos are allowed (determined by Project limitations), and 3) who has push access to those repos (determined by your SCM provider configuration).

Credits

Disclosed by ADA Logics in a security audit of the Argo project sponsored by CNCF and facilitated by OSTIF. Thanks to Adam Korczynski and David Korczynski for their work on the audit.

For more information

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS v3 base metrics

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.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVE ID

CVE-2022-31016

Credits