CVE-2019-1842· NVD / CVE Program· CNA cisco

Cisco IOS XR Software Secure Shell Authentication Vulnerability

Noroxi assessment

Priority: Monitor (action score 21/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 1.1% (FIRST EPSS); higher than 67.3% of all records.
Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
According to the record, no fixed version is available yet.
Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Update when a fix is released; follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

MediumCVSS 5.4 · v3.1—No exploit No fix recorded

Broken access control (IDOR)

BDU:2019-02129

Published: Jun 5, 2019
Updated: Jun 16, 2026
EPSS: 1.1% · 67th percentile
CWE: CWE-285

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 21 / 40 · 5.4 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 1.1%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: 5.4
CNA · cisco: 5.4; agree

CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
cisco	ios xr firmware	cpe:2.3:o:cisco:ios_xr_firmware
cisco	asr 9001	cpe:2.3:h:cisco:asr_9001
cisco	asr 9006	cpe:2.3:h:cisco:asr_9006
cisco	asr 9010	cpe:2.3:h:cisco:asr_9010
cisco	asr 9901	cpe:2.3:h:cisco:asr_9901
cisco	asr 9904	cpe:2.3:h:cisco:asr_9904
cisco	asr 9906	cpe:2.3:h:cisco:asr_9906
cisco	asr 9910	cpe:2.3:h:cisco:asr_9910
cisco	asr 9912	cpe:2.3:h:cisco:asr_9912
cisco	asr 9922	cpe:2.3:h:cisco:asr_9922
cisco	crs-1 16-slot line card chassis	cpe:2.3:h:cisco:crs-1_16-slot_line_card_chassis
cisco	crs-1 16-slot single-shelf system	cpe:2.3:h:cisco:crs-1_16-slot_single-shelf_system

and 17 more

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

cisco ios xr firmware6.1.2.tools
cisco ios xr firmware6.1.3.tools
cisco ios xr firmware6.2.3.tools
cisco ios xr firmware6.4.2.tools

Versions reported by the vendor

Affected version ranges reported by the assigning authority (cisco). Independent of NVD's CPE analysis and usually ahead of it.

Cisco Cisco IOS XR Software
- unspecified and later · before 6.1.4affected

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

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Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).