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Fencer Vulns
medium 6.1

CVE-2021-24964 json

LiteSpeed Cache < 4.4.4 - IP Check Bypass to Unauthenticated Stored XSS

published 2022-01-03 4 y ago modified 2026-06-17 4 mo ago also EUVD-2021-11876

cvss
6.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.2%
EPSS 1.2% chance of exploitation in 30 days, percentile 69%
public exploits
0
none known

Summary

The LiteSpeed Cache WordPress plugin before 4.4.4 does not properly verify that requests are coming from QUIC.cloud servers, allowing attackers to make requests to certain endpoints by using a specific X-Forwarded-For header value. In addition, one of the endpoint could be used to set CSS code if a setting is enabled, which will then be output in some pages without being sanitised and escaped. Combining those two issues, an unauthenticated attacker could put Cross-Site Scripting payloads in pages visited by users.

Patch / fix

  • litespeedtech litespeed_cache 4.4.4

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
17 mo ago

Exploit prediction

1.24% chance of exploitation in the next 30 days, higher than 69% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • wpscan.com https://wpscan.com/vulnerability/e9966b3e-2eb9-4d70-8c18-6a829b4827cc referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CISA ADP 3.1 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
NVD 3.1 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CNA 3.1 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
NVD 2.0 2.6 AV:N/AC:H/Au:N/C:N/I:P/A:N

Affected products

  • Unknown LiteSpeed Cache

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.