description: 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.
problem types: Improper Verification of Cryptographic Signature
affected:
{
vendor: Cisco
product: Cisco IOS XR Software
versions:
version: 7.5.3, status: affected
version: 7.5.2, status: affected
version: 7.5.4, status: affected
version: 7.7.1, status: affected
version: 7.7.2, status: affected
version: 7.7.21, status: affected
version: 7.8.1, status: affected
version: 7.8.2, status: affected
version: 7.9.1, status: affected
version: 7.9.2, status: affected
}
metrics:
format: cvssV3_1
cvssV3_1: [
version: 3.1
vectorString: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:N
baseScore: 5.7
baseSeverity: MEDIUM
attackVector: LOCAL
attackComplexity: HIGH
privilegesRequired: HIGH
userInteraction: NONE
scope: UNCHANGED
confidentialityImpact: HIGH
integrityImpact: HIGH
availabilityImpact: NONE
]
exploits: The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.