CVE-2020-15237: Shrinerb Shrine

Medium severity, CVSS 5.9. EPSS: 1% chance of exploitation in the next 30 days.

In Shrine before version 3.3.0, when using the `derivation_endpoint` plugin, it's possible for the attacker to use a timing attack to guess the signature of the derivation URL. The problem has been fixed by comparing sent and calculated signature in constant time, using `Rack::Utils.secure_compare`. Users using the `derivation_endpoint` plugin are urged to upgrade to Shrine 3.3.0 or greater. A possible workaround is provided in the linked advisory.

Affected products

• Shrinerb Shrine: before 3.3.0 (fixed in 3.3.0)

Published 2020-10-05. Last modified 2026-06-17.