CVE Vulnerabilities

CVE-2023-20135

Time-of-check Time-of-use (TOCTOU) Race Condition

Published: Sep 13, 2023 | Modified: Jan 25, 2024
CVSS 3.x
7
HIGH
Source:
NVD
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS 2.x
RedHat/V2
RedHat/V3
Ubuntu

A vulnerability in Cisco IOS XR Software image verification checks could allow an authenticated, local attacker to execute arbitrary code on the underlying operating system. This vulnerability is due to a time-of-check, time-of-use (TOCTOU) race condition when an install query regarding an ISO image is performed during an install operation that uses an ISO image. An attacker could exploit this vulnerability by modifying an ISO image and then carrying out install requests in parallel. A successful exploit could allow the attacker to execute arbitrary code on an affected device.

Weakness

The product checks the state of a resource before using that resource, but the resource’s state can change between the check and the use in a way that invalidates the results of the check. This can cause the product to perform invalid actions when the resource is in an unexpected state.

Affected Software

Name Vendor Start Version End Version
Ios_xr Cisco 7.5.2 (including) 7.6 (excluding)
Ios_xr Cisco 7.7 (including) 7.10.1 (excluding)

Potential Mitigations

References