CVE-2019-1842

What it is

A vulnerability in the Secure Shell (SSH) authentication function of Cisco IOS XR Software could allow an authenticated, remote attacker to successfully log in to an affected device using two distinct usernames. The vulnerability is due to a logic error that may occur when certain sequences of actions are processed during an SSH login event on the affected device. An attacker could exploit this vulnerability by initiating an SSH session to the device with a specific sequence that presents the two usernames. A successful exploit could result in logging data misrepresentation, user enumeration, or, in certain circumstances, a command authorization bypass. See the Details section for more information.

At a glance

Exploitability

Can be exploited over the network with a low-privilege account. Limited direct impact.

Exploit odds

1.2% chance of exploitation in the next 30 days (EPSS).

Fix

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

Timeline

1. 2019-06-05 17:29 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 02:29 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 1.2% in the next 30 days (EPSS).
• Severity: 5.4 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2019-06-05 17:29 UTC

Last modified

2026-06-17 02:29 UTC

Exploit probability

1.2% · EPSS, next 30 days

Weakness

CWE-285

Record status

Modified

Affected

• Cisco iOS Xr Firmware 6.1.2.tools
• Cisco iOS Xr Firmware 6.1.3.tools
• Cisco iOS Xr Firmware 6.2.3.tools
• Cisco iOS Xr Firmware 6.4.2.tools

Attack profile CVSS 3.1 · 5.4

Attack vector

Network

Complexity

Low

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

Low

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-2019-1842.md and follow it. Check whether this project is affected by CVE-2019-1842. 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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