CVE-2017-3857 Denial of service in Cisco IOS and IOS XE

High 7.5 Published Updated

Remote attackers can cause device reloads via crafted L2TP packets if the L2TP feature is enabled, requiring network administrators to apply patches.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
Not needed
Fix
None listed

What is CVE-2017-3857?

CVE-2017-3857 is a high-severity denial of service vulnerability in Cisco Ios, published on 22 Mar 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A vulnerability in the Layer 2 Tunneling Protocol (L2TP) parsing function of Cisco IOS (12.0 through 12.4 and 15.0 through 15.6) and Cisco IOS XE (3.1 through 3.18) could allow an unauthenticated, remote attacker to cause an affected device to reload. The vulnerability is due to insufficient validation of L2TP packets. An attacker could exploit this vulnerability by sending a crafted L2TP packet to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a denial of service (DoS) condition. This vulnerability affects Cisco devices that are running a vulnerable release of Cisco IOS or Cisco IOS XE Software if the L2TP feature is enabled for the device and the device is configured as an L2TP Version 2 (L2TPv2) or L2TP Version 3 (L2TPv3) endpoint. By default, the L2TP feature is not enabled. Cisco Bug IDs: CSCuy82078.

Weakness: CWE-400, CWE-399

Which versions are affected by CVE-2017-3857?

It affects 2 products.

Products include Cisco Ios, Cisco Ios Xe.

How do I fix CVE-2017-3857?

No fix has been published for CVE-2017-3857 yet. Limit exposure of the affected software until one is available.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2017-3857 being exploited?

There is no known exploitation of CVE-2017-3857 in the wild and no public exploit code.

All Cisco Ios vulnerabilities

Sources

Also known as GHSA-8hj8-9m54-wvpw.

Is CVE-2017-3857 in your software?

Upload an SBOM and sbomify checks it against every vulnerability here, every day.

Check your SBOMs for free