# CVE-2019-1887: Cisco Unified Communications Manager Session Initiation Protocol Denial of Service Vulnerability

> Unauthenticated remote attackers can cause a denial of service by sending malformed SIP packets, disrupting phone registrations in Cisco Unified Communications Manager.

- **Severity:** High 8.6 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 6 Jul 2019
- **Updated:** 19 Nov 2024
- **Also known as:** GHSA-v6rv-mppr-vw2j

## What is CVE-2019-1887?

CVE-2019-1887 is a high-severity denial of service vulnerability in Cisco Unified Communications Manager, published on 6 Jul 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in the Session Initiation Protocol (SIP) protocol implementation of Cisco Unified Communications Manager could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to insufficient validation of input SIP traffic. An attacker could exploit this vulnerability by sending a malformed SIP packet to an affected Cisco Unified Communications Manager. A successful exploit could allow the attacker to trigger a new registration process on all connected phones, temporarily disrupting service.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2019-1887?

It affects 1 product.


Products: Cisco Unified Communications Manager.

## How do I fix CVE-2019-1887?

No fix has been published for CVE-2019-1887 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-1887 being exploited?

There is no known exploitation of CVE-2019-1887 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Unified Communications Manager

- [CVE-2026-20230](https://insights.sbomify.com/CVE-2026-20230/): Cisco Unified Communications Manager Server-Side Request Forgery (SSRF) (high 8.6, exploited in the wild)
- [CVE-2026-20045](https://insights.sbomify.com/CVE-2026-20045/): Cisco Unified Communications Products Code Injection (high 8.2, exploited in the wild)
- [CVE-2025-20309](https://insights.sbomify.com/CVE-2025-20309/): Cisco Unified Communications Manager Static SSH Credentials Vulnerability (critical 10.0)
- [CVE-2011-1643](https://insights.sbomify.com/CVE-2011-1643/): Information disclosure in n/a (critical 10.0)
- [CVE-2024-20253](https://insights.sbomify.com/CVE-2024-20253/): Deserialization in Cisco Packaged Contact Center Enterprise (critical 9.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-1887 and fix it if it is affected.

What it is: CVE-2019-1887 is a high-severity denial of service vulnerability in Cisco Unified Communications Manager, published on 6 Jul 2019. 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-2019-1887 in the wild and no public exploit code.

Affected product: Cisco Unified Communications Manager. 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-2019-1887/ (Markdown: https://insights.sbomify.com/CVE-2019-1887/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-1887
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-1887
- OSV: https://osv.dev/vulnerability/CVE-2019-1887

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-1887/
Summaries are generated and may contain mistakes; the official description above is the record.