CVE-2019-1842
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.
Does this matter?
Lower severity and a low EPSS score (1.19%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 5.4 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
- EPSS
- 1.19% probability · 68th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-285, CWE-287
- Affected
- cisco/ios xr firmware
- Source
- psirt@cisco.com
EPSS 1.2% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- http://www.securityfocus.com/bid/108687Third Party Advisory, VDB Entry
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190605-iosxr-sshVendor Advisory
- http://www.securityfocus.com/bid/108687Third Party Advisory, VDB Entry
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190605-iosxr-sshVendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.