# CVE-2020-24660: Lack of URL normalization may lead to authorization bypass when URL access rules are used

> Attackers can bypass URL-based access controls on protected virtual hosts by submitting non-normalized URIs when using NGINX.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 14 Sep 2020
- **Updated:** 4 Aug 2024
- **Also known as:** DEBIAN-CVE-2020-24660, DLA-2367-1, DSA-4762-1, GHSA-x44x-r84w-8v67, UBUNTU-CVE-2020-24660

## What is CVE-2020-24660?

CVE-2020-24660 is a critical authentication bypass vulnerability in Debian Debian Linux, published on 14 Sep 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An issue was discovered in LemonLDAP::NG through 2.0.8, when NGINX is used. An attacker may bypass URL-based access control to protected Virtual Hosts by submitting a non-normalized URI. This also affects versions before 0.5.2 of the "Lemonldap::NG handler for Node.js" package.

Weakness: CWE-425 (Direct Request)

## Which versions are affected by CVE-2020-24660?

2 open source packages ship an affected version, including lemonldap-ng-handler. It affects 2 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `lemonldap-ng-handler` | npm | All versions | 0.5.2 |
| `lemonldap-ng-handler` | npm | All versions | 0.5.2 |

Products: Debian Debian Linux, Lemonldap-Ng Lemonldap\.

## How do I fix CVE-2020-24660?

Upgrade lemonldap-ng-handler to 0.5.2 or later.

## Is CVE-2020-24660 being exploited?

There is no known exploitation of CVE-2020-24660 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-24660 and fix it if it is affected.

What it is: CVE-2020-24660 is a critical authentication bypass vulnerability in Debian Debian Linux, published on 14 Sep 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-24660 in the wild and no public exploit code.

Affected packages and fixed versions:
- lemonldap-ng-handler (npm): affected all versions; fixed in 0.5.2
- lemonldap-ng-handler (npm): affected all versions; fixed in 0.5.2

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-2020-24660/ (Markdown: https://insights.sbomify.com/CVE-2020-24660/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-24660
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-24660
- OSV: https://osv.dev/vulnerability/CVE-2020-24660

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-24660/
Summaries are generated and may contain mistakes; the official description above is the record.