CVE-2018-0353

What it is

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.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data exposure.

Exploit odds

3.8% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2018-06-07 12:29 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 01:30 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 3.8% in the next 30 days (EPSS).
• Severity: 7.5 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2018-06-07 12:29 UTC

Last modified

2026-06-17 01:30 UTC

Exploit probability

3.8% · EPSS, next 30 days

Weakness

CWE-254

Record status

Modified

Affected

• Cisco Web Security Appliance 10.5.1
• Cisco Web Security Appliance 10.5.1-296
• Cisco Web Security Appliance 10.5.2
• Cisco Web Security Appliance 11.0.0
• Cisco Web Security Appliance 11.5.0-fcs-442

Attack profile CVSS 3.0 · 7.5

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2018-0353.md and follow it. Check whether this project is affected by CVE-2018-0353. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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