Cisco IOS XR Software Remote Code Execution Vulnerability (regreSSHion) (cisco cisco-sa-openssh-rce-2024)

high Nessus Plugin ID 310725

Synopsis

The remote device is missing a vendor-supplied security patch

Description

According to its self-reported version, Cisco IOS XR Software is affected by a vulnerability.

- A remote code execution vulnerability exists in Cisco IOS XR Software due to a signal handler race condition found in sshd, where a client does not authenticate within LoginGraceTime seconds, after which the sshd SIGALRM handler is called asynchronously. An unauthenticated, remote attacker can exploit this to call various functions that are not async-signal-safe with root privileges. (CVE-2024-6387)

Please see the included Cisco BIDs and Cisco Security Advisory for more information.

Solution

Upgrade to the relevant fixed version referenced in Cisco bug ID CSCwk62108

See Also

http://www.nessus.org/u?1ac35fe1

https://bst.cloudapps.cisco.com/bugsearch/bug/CSCwk62108

Plugin Details

Severity: High

ID: 310725

File Name: cisco-sa-openssh-rce-2024-iosxr.nasl

Version: 1.1

Type: Combined

Family: CISCO

Published: 4/28/2026

Updated: 4/28/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Critical

Score: 9.0

CVSS v2

Risk Factor: High

Base Score: 7.6

Vector: CVSS2#AV:N/AC:H/Au:N/C:C/I:C/A:C

CVSS Score Source: CVE-2024-6387

CVSS v3

Risk Factor: High

Base Score: 8.1

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

Vulnerability Information

CPE: cpe:/o:cisco:ios_xr

Required KB Items: Host/Cisco/IOS-XR/Version, Host/Cisco/IOS-XR/Model

Patch Publication Date: 7/1/2024

Vulnerability Publication Date: 7/1/2024

Reference Information

CVE: CVE-2024-6387

CISCO-SA: cisco-sa-openssh-rce-2024

IAVA: 2024-A-0375-S

CISCO-BUG-ID: CSCwk62108