# CVE-2018-0353: Security feature bypass in Cisco Web Security Appliance unknown

> Unauthenticated attackers can bypass Layer 4 Traffic Monitor protections on Cisco WSA by sending crafted IP packets, allowing denied traffic to pass through.

- **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:** 7 Jun 2018
- **Updated:** 29 Nov 2024
- **Also known as:** GHSA-jh9h-rrv2-x586

## What is CVE-2018-0353?

CVE-2018-0353 is a high-severity vulnerability in Cisco Web Security Appliance, published on 7 Jun 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in traffic-monitoring functions in Cisco Web Security Appliance (WSA) could allow an unauthenticated, remote attacker to circumvent Layer 4 Traffic Monitor (L4TM) functionality and bypass security protections. The vulnerability is due to a change in the underlying operating system software that is responsible for monitoring affected traffic. An attacker could exploit this vulnerability by sending crafted IP packets to an affected device. A successful exploit could allow the attacker to pass traffic through the device, which the WSA was configured to deny. This vulnerability affects both IPv4 and IPv6 traffic. This vulnerability affects Cisco AsyncOS versions for WSA on both virtual and hardware appliances running any release of the 10.5.1, 10.5.2, or 11.0.0 WSA Software. The WSA is vulnerable if it is configured for L4TM. Cisco Bug IDs: CSCvg78875.

Weakness: CWE-254

## Which versions are affected by CVE-2018-0353?

It affects 1 product.


Products: Cisco Web Security Appliance.

## How do I fix CVE-2018-0353?

No fix has been published for CVE-2018-0353 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-0353 being exploited?

There is no known exploitation of CVE-2018-0353 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Web Security Appliance

- [CVE-2015-6298](https://insights.sbomify.com/CVE-2015-6298/): Command injection in n/a (critical 9.0)
- [CVE-2019-1817](https://insights.sbomify.com/CVE-2019-1817/): Cisco Web Security Appliance Malformed Request Denial of Service Vulnerability (high 8.6)
- [CVE-2018-0410](https://insights.sbomify.com/CVE-2018-0410/): Denial of service in AsyncOS Software for Cisco Web Security Appliances (high 8.6)
- [CVE-2015-6292](https://insights.sbomify.com/CVE-2015-6292/): Denial of service in n/a (high 7.8)
- [CVE-2015-6293](https://insights.sbomify.com/CVE-2015-6293/): Denial of service in n/a (high 7.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-0353 and fix it if it is affected.

What it is: CVE-2018-0353 is a high-severity vulnerability in Cisco Web Security Appliance, published on 7 Jun 2018. 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-2018-0353 in the wild and no public exploit code.

Affected product: Cisco Web Security Appliance. 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-2018-0353/ (Markdown: https://insights.sbomify.com/CVE-2018-0353/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-0353
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-0353
- OSV: https://osv.dev/vulnerability/CVE-2018-0353

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-0353/
Summaries are generated and may contain mistakes; the official description above is the record.