CVE-2013-6451Public exploitNetwork attack vector

Cross-site scripting via fullwidth-backslash sanitizer bypass

Published Jan 28, 2020 · Updated Aug 6, 2024

Cross-site scripting in MediaWiki 1.19.9, 1.20.x, through 1.21.3, and 1.22.0 allows remote attackers to inject script via CSS. Sanitizer::checkCss normalizes a fullwidth reverse solidus after decoding CSS escapes, so crafted values evade its blacklist. Exploitation requires a user to render the crafted content; injected code then runs in the affected wiki's browser origin.

CVSS severity6.1
Medium
EPSS probability1.08%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in MediaWiki 1.19.9, 1.20.x, through 1.21.3, and 1.22.0 allows remote attackers to inject script via CSS. Sanitizer::checkCss normalizes a fullwidth reverse solidus after decoding CSS escapes, so crafted values evade its blacklist. Exploitation requires a user to render the crafted content; injected code then runs in the affected wiki's browser origin.

The record

CVE
CVE-2013-6451
Published
Jan 28, 2020
Updated
Aug 6, 2024
Vendor
Wikimedia Foundation
Product
MediaWiki
Classifications
CWE-79, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 28, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 6, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.19.9 before 1.19.10
  2. Affected versionversion=1.22.x before 1.22.1
  3. Affected versionversion=1.2x before 1.21.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Wikimedia Foundation · MediaWikiversion=1.19.9 before 1.19.10; version=1.22.x before 1.22.1; version=1.2x before 1.21.4

Published CVSS scores

4.3NIST National Vulnerability DatabaseAV:N/AC:M/Au:N/C:N/I:P/A:N
6.1NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1189Drive-by Compromise

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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