# CVE-2023-28126: Auth bypass in Avalanche

> Attackers can bypass authentication in Avalanche servers via race conditions or SetUser exploitation, gaining unauthorized access.

- **Severity:** Medium 5.9 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 9 May 2023
- **Updated:** 29 Jan 2025
- **Also known as:** GHSA-9mhq-xcrq-xc75

## What is CVE-2023-28126?

CVE-2023-28126 is a medium-severity authentication bypass vulnerability in Ivanti Avalanche, published on 9 May 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An authentication bypass vulnerability exists in Avalanche versions 6.3.x and below that could allow an attacker to gain access by exploiting the SetUser method or can exploit the Race Condition in the authentication message.

Weakness: CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization), CWE-305 (Authentication Bypass by Primary Weakness)

## Which versions are affected by CVE-2023-28126?

It affects 1 product.


Products: Ivanti Avalanche.

## How do I fix CVE-2023-28126?

No fix has been published for CVE-2023-28126 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-28126 being exploited?

There is no known exploitation of CVE-2023-28126 in the wild and no public exploit code.

## Other vulnerabilities in Ivanti Avalanche

- [CVE-2023-38036](https://insights.sbomify.com/CVE-2023-38036/): Memory corruption in Avalanche (critical 9.8)
- [CVE-2024-24996](https://insights.sbomify.com/CVE-2024-24996/): Memory corruption in Avalanche (critical 9.8)
- [CVE-2024-29204](https://insights.sbomify.com/CVE-2024-29204/): Memory corruption in Avalanche (critical 9.8)
- [CVE-2023-41727](https://insights.sbomify.com/CVE-2023-41727/): Memory corruption in Wavelink (critical 9.8)
- [CVE-2023-46216](https://insights.sbomify.com/CVE-2023-46216/): Memory corruption in Wavelink (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-28126 and fix it if it is affected.

What it is: CVE-2023-28126 is a medium-severity authentication bypass vulnerability in Ivanti Avalanche, published on 9 May 2023. 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-2023-28126 in the wild and no public exploit code.

Affected product: Ivanti Avalanche. 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-2023-28126/ (Markdown: https://insights.sbomify.com/CVE-2023-28126/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-28126
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-28126
- OSV: https://osv.dev/vulnerability/CVE-2023-28126

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-28126/
Summaries are generated and may contain mistakes; the official description above is the record.