CVE-2017-3793

What it is

A vulnerability in the TCP normalizer of Cisco Adaptive Security Appliance (ASA) Software (8.0 through 8.7 and 9.0 through 9.6) and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause Cisco ASA and FTD to drop any further incoming traffic on all interfaces, resulting in a denial of service (DoS) condition. The vulnerability is due to improper limitation of the global out-of-order TCP queue for specific block sizes. An attacker could exploit this vulnerability by sending a large number of unique permitted TCP connections with out-of-order segments. An exploit could allow the attacker to exhaust available blocks in the global out-of-order TCP queue, causing the dropping of any further incoming traffic on all interfaces and resulting in a DoS condition. Cisco Bug IDs: CSCvb46321.

At a glance

Exploitability

Can be exploited over the network without logging in. Limited direct impact.

Exploit odds

1.7% chance of exploitation in the next 30 days (EPSS).

Fix

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

Timeline

1. 2017-04-20 22:59 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 01:18 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 1.7% in the next 30 days (EPSS).
• Severity: 4.0 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2017-04-20 22:59 UTC

Last modified

2026-06-17 01:18 UTC

Exploit probability

1.7% · EPSS, next 30 days

Weakness

CWE-399

Record status

Modified

Affected

• Cisco Adaptive Security Appliance Software 8.0.1.2
• Cisco Adaptive Security Appliance Software 8.0.2
• Cisco Adaptive Security Appliance Software 8.0.2.11
• Cisco Adaptive Security Appliance Software 8.0.2.15
• Cisco Adaptive Security Appliance Software 8.0.3
• Cisco Adaptive Security Appliance Software 8.0.3.6
• Cisco Adaptive Security Appliance Software 8.0.3.12
• Cisco Adaptive Security Appliance Software 8.0.3.19

Attack profile CVSS 3.0 · 4.0

Attack vector

Network

Complexity

High

Privileges needed

None

User interaction

None

Scope

Changed

Confidentiality

None

Integrity

None

Availability

Low

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-2017-3793.md and follow it. Check whether this project is affected by CVE-2017-3793. 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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