# CVE-2015-6421: Denial of service in n/a

> Remote attackers can cause denial of service and device reload on Cisco WAAS devices via crafted network traffic.

- **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:** 27 Jan 2016
- **Updated:** 6 Aug 2024
- **Also known as:** GHSA-6f4r-2cf4-2gv2

## What is CVE-2015-6421?

CVE-2015-6421 is a high-severity denial of service vulnerability in n/a, published on 27 Jan 2016. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

cifs-ao in the CIFS optimization functionality on Cisco Wide Area Application Service (WAAS) and Virtual WAAS (vWAAS) devices 5.x before 5.3.5d and 5.4 and 5.5 before 5.5.3 allows remote attackers to cause a denial of service (resource consumption and device reload) via crafted network traffic, aka Bug ID CSCus85330.

Weakness: CWE-399

## Which versions are affected by CVE-2015-6421?

It affects 1 product.


Products: Cisco Wide Area Application Services.

## How do I fix CVE-2015-6421?

No fix has been published for CVE-2015-6421 yet. Limit exposure of the affected software until one is available.

## Is CVE-2015-6421 being exploited?

There is no known exploitation of CVE-2015-6421 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2013-3443](https://insights.sbomify.com/CVE-2013-3443/): Code injection in n/a (critical 10.0)
- [CVE-2014-2196](https://insights.sbomify.com/CVE-2014-2196/): Code injection in n/a (critical 9.3)
- [CVE-2007-3923](https://insights.sbomify.com/CVE-2007-3923/): Denial of service in n/a (high 7.8)
- [CVE-2017-6628](https://insights.sbomify.com/CVE-2017-6628/): Denial of service in Cisco Wide Area Application Services SMART-SSL Accelerator (medium 6.8)
- [CVE-2018-0352](https://insights.sbomify.com/CVE-2018-0352/): Privilege escalation in Cisco Wide Area Application Services unknown (medium 6.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2015-6421 and fix it if it is affected.

What it is: CVE-2015-6421 is a high-severity denial of service vulnerability in n/a, published on 27 Jan 2016. 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-2015-6421 in the wild and no public exploit code.

Affected product: n/a. 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-2015-6421/ (Markdown: https://insights.sbomify.com/CVE-2015-6421/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2015-6421
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2015-6421
- OSV: https://osv.dev/vulnerability/CVE-2015-6421

---
From sbomify Insights: https://insights.sbomify.com/CVE-2015-6421/
Summaries are generated and may contain mistakes; the official description above is the record.