# CVE-2017-6731: Denial of service in Cisco IOS XR

> An unauthenticated remote attacker can cause a short denial of service by resetting the MSDP session in Cisco IOS XR.

- **Severity:** High 7.5 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/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:** 10 Jul 2017
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-qvcw-7x8x-4p95

## What is CVE-2017-6731?

CVE-2017-6731 is a high-severity denial of service vulnerability in Cisco Ios Xr, published on 10 Jul 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in Multicast Source Discovery Protocol (MSDP) ingress packet processing for Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause the MSDP session to be unexpectedly reset, causing a short denial of service (DoS) condition. The MSDP session will restart within a few seconds. More Information: CSCvd94828. Known Affected Releases: 4.3.2.MCAST 6.0.2.BASE. Known Fixed Releases: 6.3.1.19i.MCAST 6.2.3.1i.MCAST 6.2.2.17i.MCAST 6.1.4.12i.MCAST.

Weakness: CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2017-6731?

It affects 1 product.


Products: Cisco Ios Xr.

## How do I fix CVE-2017-6731?

No fix has been published for CVE-2017-6731 yet. Limit exposure of the affected software until one is available.

## Is CVE-2017-6731 being exploited?

There is no known exploitation of CVE-2017-6731 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Ios Xr

- [CVE-2020-3118](https://insights.sbomify.com/CVE-2020-3118/): Cisco IOS XR Software Discovery Protocol Format String (high 8.8, exploited in the wild)
- [CVE-2020-3569](https://insights.sbomify.com/CVE-2020-3569/): Cisco IOS XR Software DVMRP Memory Exhaustion (high 8.6, exploited in the wild)
- [CVE-2020-3566](https://insights.sbomify.com/CVE-2020-3566/): Cisco IOS XR Software DVMRP Memory Exhaustion (high 8.6, exploited in the wild)
- [CVE-2010-3035](https://insights.sbomify.com/CVE-2010-3035/): Cisco IOS XR Border Gateway Protocol (BGP) Denial-of-Service (high 7.5, exploited in the wild)
- [CVE-2022-20821](https://insights.sbomify.com/CVE-2022-20821/): Cisco IOS XR Open Port (medium 6.5, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2017-6731 and fix it if it is affected.

What it is: CVE-2017-6731 is a high-severity denial of service vulnerability in Cisco Ios Xr, published on 10 Jul 2017. 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-2017-6731 in the wild and no public exploit code.

Affected product: Cisco Ios Xr. 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-2017-6731/ (Markdown: https://insights.sbomify.com/CVE-2017-6731/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2017-6731
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-6731
- OSV: https://osv.dev/vulnerability/CVE-2017-6731

---
From sbomify Insights: https://insights.sbomify.com/CVE-2017-6731/
Summaries are generated and may contain mistakes; the official description above is the record.