CVE-2019-1842

Cisco IOS XR Software Secure Shell Authentication Vulnerability

MEDIUM
5.4
CVSS Score
Published: June 5, 2019 at 04:20 PM UTC
Updated: June 17, 2026 at 02:29 AM UTC
30 products affected across 1 vendorIOS Xr FirmwareAsr 9010Asr 9904

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Severity
MEDIUM5.4
Exploit prediction
EPSS 1%
SSVC
No known exploit

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

cisco-asr-9001 (environment) · cisco-asr-9006 (environment) · cisco-asr-9010 (environment) · cisco-asr-9901 (environment) · cisco-asr-9904 (environment) · cisco-asr-9906 (environment) · cisco-asr-9910 (environment) · cisco-asr-9912 (environment) · cisco-asr-9922 (environment) · cisco-crs-1-16-slot-line-card-chassis (environment) · cisco-crs-1-16-slot-single-shelf-system (environment) · cisco-crs-1-4-slot-single-shelf-system (environment) · cisco-crs-1-8-slot-line-card-chassis (environment) · cisco-crs-1-8-slot-single-shelf-system (environment) · cisco-crs-1-fabric-card-chassis (environment) · cisco-crs-1-line-card-chassis-dual (environment) · cisco-crs-1-line-card-chassis-multi (environment) · cisco-crs-1-multishelf-system (environment) · cisco-crs-3-16-slot-single-shelf-system (environment) · cisco-crs-3-4-slot-single-shelf-system (environment) · cisco-crs-3-8-slot-single-shelf-system (environment) · cisco-crs-3-multishelf-system (environment) · cisco-crs-8-s-b-crs (environment) · cisco-crs-8-scrs (environment) · cisco-crs-x-16-slot-single-shelf-system (environment) · cisco-crs-x-multishelf-system (environment) · cisco-ncs-6008-8-slot-chassis (environment) · cisco-network-convergence-system-5508 (environment)
v < 6.1.4
Affected range stops below 6.1.4, so it looks safe — our inference, not a vendor statement
All versions
All versions
All versions
All versions
All versions
All versions
All versions
All versions

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-285CWE-287

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