CVE-2020-15237

Name: CVE-2020-15237
Creator: NVD / NIST
Published: 2020-10-05T19:15:15.103+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.9/10EPSS 1.00%

Last modified Jun 17, 2026

CVE-2020-15237 is a medium-severity vulnerability rated 5.9/10 on the CVSS scale. 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`. EPSS estimates a 1.00% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1

5.9/10

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS Probability

1.00%

58.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Shrinerb	Shrine	< 3.3.0

References

https://github.com/shrinerb/shrine/commit/1b27090ce31543bf39f186c20ea47c8250fca2f0Patch, Third Party Advisory
https://github.com/shrinerb/shrine/security/advisories/GHSA-5jjv-x4fq-qjwpThird Party Advisory
https://github.com/shrinerb/shrine/commit/1b27090ce31543bf39f186c20ea47c8250fca2f0Patch, Third Party Advisory
https://github.com/shrinerb/shrine/security/advisories/GHSA-5jjv-x4fq-qjwpThird Party Advisory

Timeline

Published: Oct 5, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-15237?

How severe is CVE-2020-15237?

CVE-2020-15237 has a CVSS score of 5.9/10 (MEDIUM severity). The EPSS model estimates a 1.00% probability of exploitation in the next 30 days.

How do I fix CVE-2020-15237?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-15237?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST