CVE-2020-15164

Name: CVE-2020-15164
Creator: NVD / NIST
Published: 2020-08-28T17:15:11.92+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 10/10EPSS 1.17%

Last modified Jun 17, 2026

CVE-2020-15164 is a critical-severity vulnerability rated 10/10 on the CVSS scale. in Scratch Login (MediaWiki extension) before version 1.1, any account can be logged into by using the same username with leading, trailing, or repeated underscore(s), since those are treated as whitespace and trimmed by MediaWiki. This affects all users on any wiki using this extension. EPSS estimates a 1.17% chance of exploitation in the next 30 days.

Description

in Scratch Login (MediaWiki extension) before version 1.1, any account can be logged into by using the same username with leading, trailing, or repeated underscore(s), since those are treated as whitespace and trimmed by MediaWiki. This affects all users on any wiki using this extension. Since version 1.1, comments by users whose usernames would be trimmed on MediaWiki are ignored when searching for the verification code.

Metrics

CVSS 3.1

10/10

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

EPSS Probability

1.17%

63.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Scratch-Wiki	Scratch Login	< 1.1

References

https://github.com/InternationalScratchWiki/mediawiki-scratch-login/commit/70849ef375016a1061490c8c4744046dbfc3e679Patch, Third Party Advisory
https://github.com/InternationalScratchWiki/mediawiki-scratch-login/security/advisories/GHSA-8fq5-g4m5-6j43Third Party Advisory
https://github.com/InternationalScratchWiki/mediawiki-scratch-login/commit/70849ef375016a1061490c8c4744046dbfc3e679Patch, Third Party Advisory
https://github.com/InternationalScratchWiki/mediawiki-scratch-login/security/advisories/GHSA-8fq5-g4m5-6j43Third Party Advisory

Timeline

Published: Aug 28, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-15164?

How severe is CVE-2020-15164?

CVE-2020-15164 has a CVSS score of 10/10 (CRITICAL severity). The EPSS model estimates a 1.17% probability of exploitation in the next 30 days.

How do I fix CVE-2020-15164?

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-2020-15164?

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

Scan your code now

Source: NVD / NIST