# CVE-2016-6422: Security feature bypass in n/a

> Remote attackers can bypass access restrictions on Cisco IOS devices by sending packets that evade TCAM share ACL filters due to improper handling of operators and keywords.

- **Severity:** High 7.5 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 6 Oct 2016
- **Updated:** 6 Aug 2024
- **Also known as:** GHSA-phhm-6h54-j6xc

## What is CVE-2016-6422?

CVE-2016-6422 is a high-severity vulnerability in Cisco Ios, published on 6 Oct 2016. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Cisco IOS 12.2(33)SXJ9 on Supervisor Engine 32 and 720 modules for 6500 and 7600 devices mishandles certain operators, flags, and keywords in TCAM share ACLs, which allows remote attackers to bypass intended access restrictions by sending packets that should have been recognized by a filter, aka Bug ID CSCuy64806.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2016-6422?

It affects 1 product.


Products: Cisco Ios.

## How do I fix CVE-2016-6422?

No fix has been published for CVE-2016-6422 yet. Limit exposure of the affected software until one is available.

## Is CVE-2016-6422 being exploited?

There is no known exploitation of CVE-2016-6422 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Ios

- [CVE-2017-12240](https://insights.sbomify.com/CVE-2017-12240/): Cisco IOS and IOS XE Software DHCP Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2017-3881](https://insights.sbomify.com/CVE-2017-3881/): Cisco IOS and IOS XE Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2018-0167](https://insights.sbomify.com/CVE-2018-0167/): Cisco IOS, XR, and XE Software Buffer Overflow (high 8.8, exploited in the wild)
- [CVE-2017-6736](https://insights.sbomify.com/CVE-2017-6736/): Cisco IOS and IOS XE Software SNMP Remote Code Execution (high 8.8, exploited in the wild)
- [CVE-2017-6737](https://insights.sbomify.com/CVE-2017-6737/): Cisco IOS and IOS XE Software SNMP Remote Code Execution (high 8.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2016-6422 and fix it if it is affected.

What it is: CVE-2016-6422 is a high-severity vulnerability in Cisco Ios, published on 6 Oct 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-2016-6422 in the wild and no public exploit code.

Affected product: Cisco Ios. 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-2016-6422/ (Markdown: https://insights.sbomify.com/CVE-2016-6422/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2016-6422
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2016-6422
- OSV: https://osv.dev/vulnerability/CVE-2016-6422

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From sbomify Insights: https://insights.sbomify.com/CVE-2016-6422/
Summaries are generated and may contain mistakes; the official description above is the record.