# CVE-2021-24964: LiteSpeed Cache < 4.4.4 - IP Check Bypass to Unauthenticated Stored XSS

> Unauthenticated attackers can inject malicious scripts via stored XSS in the LiteSpeed Cache plugin when specific settings are enabled, potentially compromising user sessions.

- **Severity:** Medium 6.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 3 Jan 2022
- **Updated:** 22 May 2025
- **Also known as:** GHSA-fg4h-vrcg-56rq

## What is CVE-2021-24964?

CVE-2021-24964 is a medium-severity cross-site scripting vulnerability in Unknown LiteSpeed Cache, published on 3 Jan 2022. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

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.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2021-24964?

It affects 1 product.


Products: Litespeedtech Litespeed Cache.

## How do I fix CVE-2021-24964?

No fix has been published for CVE-2021-24964 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-24964 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-24964 exists.

## Other vulnerabilities in Unknown LiteSpeed Cache

- [CVE-2024-44000](https://insights.sbomify.com/CVE-2024-44000/): WordPress LiteSpeed Cache plugin < 6.5.0.1 - Unauthenticated Account Takeover via Cookie Leak vulnerability (critical 9.8)
- [CVE-2024-28000](https://insights.sbomify.com/CVE-2024-28000/): WordPress LiteSpeed Cache plugin <= 6.3.0.1 - Unauthenticated Privilege Escalation vulnerability (critical 9.8)
- [CVE-2024-47637](https://insights.sbomify.com/CVE-2024-47637/): WordPress LiteSpeed Cache plugin <= 6.4.1 - Path Traversal vulnerability (high 8.8)
- [CVE-2023-40000](https://insights.sbomify.com/CVE-2023-40000/): WordPress LiteSpeed Cache plugin <= 5.7 - Unauthenticated Site Wide Stored XSS vulnerability (high 8.3)
- [CVE-2023-45000](https://insights.sbomify.com/CVE-2023-45000/): WordPress LiteSpeed Cache plugin <= 5.7 - Unauthenticated Broken Access Control on API vulnerability (high 8.2)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-24964 and fix it if it is affected.

What it is: CVE-2021-24964 is a medium-severity cross-site scripting vulnerability in Unknown LiteSpeed Cache, published on 3 Jan 2022. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-24964 exists.

Affected product: Unknown LiteSpeed Cache. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2021-24964/ (Markdown: https://insights.sbomify.com/CVE-2021-24964/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-24964
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-24964
- OSV: https://osv.dev/vulnerability/CVE-2021-24964

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-24964/
Summaries are generated and may contain mistakes; the official description above is the record.