Action Mailer is a framework for designing email service layers. Starting in version 3.0.0 and prior to versions 6.1.7.9, 7.0.8.5, 7.1.4.1, and 7.2.1.1, there is a possible ReDoS vulnerability in the block_format helper in Action Mailer. Carefully crafted text can cause the block_format helper to take an unexpected amount of time, possibly resulting in a DoS vulnerability. All users running an affected release should either upgrade to versions 6.1.7.9, 7.0.8.5, 7.1.4.1, or 7.2.1.1 or apply the relevant patch immediately. As a workaround, users can avoid calling the `block_format` helper or upgrade to Ruby 3.2. Ruby 3.2 has mitigations for this problem, so Rails applications using Ruby 3.2 or newer are unaffected. Rails 8.0.0.beta1 requires Ruby 3.2 or greater so is unaffected.
https://github.com/rails/rails/security/advisories/GHSA-h47h-mwp9-c6q6
https://github.com/rails/rails/commit/be898cc996986decfe238341d96b2a6573b8fd2e
https://github.com/rails/rails/commit/985f1923fa62806ff676e41de67c3b4552131ab9
https://github.com/rails/rails/commit/3612e3eb3fbafed4f85e1c6ea4c7b6addbb0fdd3
https://github.com/rails/rails/commit/0e5694f4d32544532d2301a9b4084eacb6986e94
Published: 2024-10-16
Updated: 2024-10-18
Base Score: 5.4
Vector: CVSS2#AV:N/AC:H/Au:N/C:N/I:N/A:C
Severity: Medium
Base Score: 5.9
Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Severity: Medium
Base Score: 8.7
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Severity: High