6.4

CVE-2021-24559: patrickposner qyrr Cross-site Scripting

CVSS: 6.4v3.1MediumModified
Published 16-01-2024Last modified 20-06-2025
Open JSON

Vulnerability summary

CVE-2021-24559 is a medium (CVSS 6.4) Cross-site Scripting vulnerability in patrickposner qyrr. EPSS estimates a 0.22% chance of exploitation in the next 30 days, higher than 11.6% of scored vulnerabilities. 1 public exploit is recorded. Fixed in 0.8.

Overall risk
36/100
0100
Medium · default modelHow is this calculated?
CVSS score
6.4/10
010
Medium · v3.1 (wordfence)
EPSS score
0.22%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1reference

Timeline

  1. 16-01-2024
    PublishedVulnerability first disclosed.
  2. 20-06-2025
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.22%

Chance of exploitation in the next 30 days

Percentile

12%

Versus all other CVEs

30-day change

0.00 pp

From 0.22% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.22%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

1 found
  • referenceUnverified

    Exploit Reference (wpscan.com)

    Maturity: unknown

Weaknesses

CWE · root cause

Affected systems

Patrickposner1 product
Unknown1 product
Wordpress1 product
  • qyrr-code≤ 0.7 (fixed in 0.8)

3 vendors · 3 products

References

2 links