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Fencer Vulns
medium 5.4

CVE-2021-24559 json

Qyrr < 0.7 - Authenticated (contributor+) Stored XSS

published 2024-01-16 2 y ago modified 2026-06-17 4 mo ago also EUVD-2021-11471

cvss
5.4
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 12%
public exploits
0
none known

Summary

The Qyrr WordPress plugin before 0.7 does not escape the data-uri of the QR Code when outputting it in a src attribute, allowing for Cross-Site Scripting attacks. Furthermore, the data_uri_to_meta AJAX action, available to all authenticated users, only had a CSRF check in place, with the nonce available to users with a role as low as Contributor allowing any user with such role (and above) to set a malicious data-uri in arbitrary QR Code posts, leading to a Stored Cross-Site Scripting issue.

Patch / fix

  • Unknown Qyrr 0.7

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.22% chance of exploitation in the next 30 days, higher than 12% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • wpscan.com https://wpscan.com/vulnerability/65a29976-163a-4bbf-a4e8-590ddc4b83f2/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CISA ADP 3.1 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
NVD 3.1 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
CNA 3.1 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Affected products

  • Unknown Qyrr

Classification

Weakness
  • CWE-79 Improper Neutralization of Input During Web Page Generation
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.