CVE-2021-34720
HIGHCisco IOS XR < 6.2.3 - Unauthenticated Denial of Service via IP SLA or TWAMP Packet Handling
Title source: llmDescription
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
Vendor Advisory vendor-advisory
x_refsource_cisco
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ipsla-ZA3SRrpP
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