Impact
GoCD versions from 19.2.0 to 19.10.0 (inclusive) are subject to a timing attack in validation of access tokens due to use of regular string comparison for validation of the token rather than a constant time algorithm. This could allow a brute force attack on GoCD server API calls to observe timing differences in validations in order to guess an access token generated by a user for API access.
Patches
Fixed in GoCD 19.11.0.
Workarounds
- Apply rate limiting or insert random delays to API calls made to GoCD Server via a reverse proxy or other fronting web server.
- Disallow use of access tokens by users by having an administrator revoke all access tokens through the "Access Token Management" admin function.
References
For more information
If you have any questions or comments about this advisory:
Impact
GoCD versions from 19.2.0 to 19.10.0 (inclusive) are subject to a timing attack in validation of access tokens due to use of regular string comparison for validation of the token rather than a constant time algorithm. This could allow a brute force attack on GoCD server API calls to observe timing differences in validations in order to guess an access token generated by a user for API access.
Patches
Fixed in GoCD 19.11.0.
Workarounds
References
For more information
If you have any questions or comments about this advisory: