CVE-2023-40165

    Dashboard / Vulnerabilities / CVE-2023-40165

    CVE-2023-40165

    Published: 17 Aug 2023Last Modified: 2 Apr 2026

    Summary: Unauthorized gem replacement for full names ending in numbers on rubygems.org

    Details: rubygems.org is the Ruby community's primary gem (library) hosting service. Insufficient input validation allowed malicious actors to replace any uploaded gem version that had a platform, version number, or gem name matching `/-\d/`, permanently replacing the legitimate upload in the canonical gem storage bucket, and triggering an immediate CDN purge so that the malicious gem would be served immediately. The maintainers have checked all gems matching the `/-\d/` pattern and can confirm that no unexpected `.gem`s were found. As a result, we believe this vulnerability was _not_ exploited. The easiest way to ensure that a user's applications were not exploited by this vulnerability is to check that all of your downloaded .gems have a checksum that matches the checksum recorded in the RubyGems.org database. RubyGems contributor Maciej Mensfeld wrote a tool to automatically check that all downloaded .gem files match the checksums recorded in the RubyGems.org database. You can use it by running: `bundle add bundler-integrity` followed by `bundle exec bundler-integrity`. Neither this tool nor anything else can prove you were not exploited, but the can assist your investigation by quickly comparing RubyGems API-provided checksums with the checksums of files on your disk. The issue has been patched with improved input validation and the changes are live. No action is required on the part of the user. Users are advised to validate their local gems.

    Affected packages

    Package

    Name:

    Purl:

    Affected ranges

    Type: GIT

    Events:

    Affected versions

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High
    CVE-2023-40165 | CVE-DB