Mojolicious

Mojolicious versions from 4.59 before 9.48 for Perl expose a stable representation of the session CSRF token to a BREACH compression oracle. _csrf_token generates and caches one token per session and returns the same value on every call, and _csrf_field places that value in a hidden `csrf_token` input. When a response carrying the token also echoes attacker-controlled input and is gzip-compressed, the chosen values and the resulting compressed lengths form a BREACH oracle. An attacker able to query it can recover the token and pass csrf_protect validation.

Published: 2026-07-14T17:07:32.593Z
Updated: 2026-07-15T16:32:58.629Z

Mojolicious versions from 7.28 through 9.45 for Perl will generate weak HMAC session cookie secrets via "mojo generate app" by default. When creating a default app skeleton with the "mojo generate app" tool, a weak secret is written to the application's configuration file using the insecure rand() function, and used for authenticating and protecting the integrity of the application's sessions. This may allow an attacker to brute force the application's session keys. Release 9.46 fixes the issue by providing high quality randomness, even in absence of CryptX. Users should be aware that the update does not replace previously generated weak secrets. A secret generated with the previous version MUST be replaced to ensure the updated version is using a strong secret.

Published: 2025-05-03T10:16:10.636Z
Updated: 2026-06-05T12:37:53.344Z

Mojolicious versions from 0.999922 for Perl uses a hard coded string, or the application's class name, as an HMAC session cookie secret by default. These predictable default secrets can be exploited by an attacker to forge session cookies.  An attacker who knows or guesses the secret could compute valid HMAC signatures for the session cookie, allowing them to tamper with or hijack another user’s session.

Published: 2025-05-03T16:08:55.042Z
Updated: 2025-10-20T20:09:00.882Z