CVE-2021-34720

HIGH

Cisco IOS XR < 6.2.3 - Unauthenticated Denial of Service via IP SLA or TWAMP Packet Handling

Title source: llm
STIX 2.1

Description

A vulnerability in the IP Service Level Agreements (IP SLA) responder and Two-Way Active Measurement Protocol (TWAMP) features of Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause device packet memory to become exhausted or cause the IP SLA process to crash, resulting in a denial of service (DoS) condition. This vulnerability exists because socket creation failures are mishandled during the IP SLA and TWAMP processes. An attacker could exploit this vulnerability by sending specific IP SLA or TWAMP packets to an affected device. A successful exploit could allow the attacker to exhaust the packet memory, which will impact other processes, such as routing protocols, or crash the IP SLA process.

References (1)

Core 1
Core References

Scores

CVSS v3 8.6
EPSS 0.0038
EPSS Percentile 59.6%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact partial

Details

CWE
CWE-771
Status published
Products (1)
cisco/ios_xr < 6.2.3
Published Sep 09, 2021
Tracked Since Feb 18, 2026