CVE-2022-29220: fastify github_action_merge_dependabot Unverified Ownership

Vulnerability summary

CVE-2022-29220 is a medium (CVSS 6.5) Unverified Ownership vulnerability in fastify github_action_merge_dependabot. EPSS estimates a 0.50% chance of exploitation in the next 30 days, higher than 41.5% of scored vulnerabilities.

Timeline

1. 31-05-2022
   PublishedVulnerability first disclosed.
2. 23-04-2025
   Last modifiedVulnerability information updated.

Description

github-action-merge-dependabot is an action that automatically approves and merges dependabot pull requests (PRs). Prior to version 3.2.0, github-action-merge-dependabot does not check if a commit created by dependabot is verified with the proper GPG key. There is just a check if the actor is set to `dependabot[bot]` to determine if the PR is a legit PR. Theoretically, an owner of a seemingly valid and legit action in the pipeline can check if the PR is created by dependabot and if their own action has enough permissions to modify the PR in the pipeline. If so, they can modify the PR by adding a second seemingly valid and legit commit to the PR, as they can set arbitrarily the username and email in for commits in git. Because the bot only checks if the actor is valid, it would pass the malicious changes through and merge the PR automatically, without getting noticed by project maintainers. It would probably not be possible to determine where the malicious commit came from, as it would only say `dependabot[bot]` and the corresponding email-address. Version 3.2.0 contains a patch for this issue.

• CWE-283Unverified OwnershipThe product does not properly verify that a critical resource is owned by the proper entity.
• CWE-345Insufficient Verification of Data AuthenticityThe product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.