CVE-2021-34720
First published: Thu Sep 09 2021(Updated: )
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.
Credit: ykramarz@cisco.com
| Affected Software | Affected Version | How to fix |
|---|---|---|
| Cisco IOS XR | <6.2.3 | |
| Cisco IOS XR | >=6.3.0<6.3.2 | |
| Cisco IOS XR | >=6.5.0<7.2.2 | |
| Cisco Asr 9000v-v2 | ||
| Cisco Asr 9001 | ||
| Cisco Asr 9006 | ||
| Cisco Asr 9010 | ||
| Cisco Asr 9901 | ||
| Cisco Asr 9902 | ||
| Cisco Asr 9903 | ||
| Cisco Asr 9904 | ||
| Cisco Asr 9906 | ||
| Cisco Asr 9910 | ||
| Cisco Asr 9912 | ||
| Cisco Asr 9922 | ||
| Cisco Ios Xrv | ||
| Cisco Ios Xrv 9000 | ||
| Cisco Ncs 520 | ||
| Cisco Ncs 540 | ||
| Cisco Ncs 540 Fronthaul | ||
| Cisco Ncs 560-4 | ||
| Cisco Ncs 560-7 | ||
| Cisco Ncs 5001 | ||
| Cisco Ncs 5002 | ||
| Cisco Ncs 5011 | ||
| Cisco Ncs 4009 | ||
| Cisco Ncs 4016 | ||
| Cisco Ncs 5501 | ||
| Cisco Ncs 5501-se | ||
| Cisco Ncs 5502 | ||
| Cisco Ncs 5502-se | ||
| Cisco Ncs 5508 | ||
| Cisco Ncs 5516 | ||
| Cisco Ncs 6000 | ||
| Cisco Ncs 6008 | ||
| Cisco Ncs 1001 | ||
| Cisco Ncs 1002 | ||
| Cisco Ncs 1004 | ||
| Cisco 8101-32fh | ||
| Cisco 8101-32h | ||
| Cisco 8102-64h | ||
| Cisco 8201 | ||
| Cisco 8201-32fh | ||
| Cisco 8202 | ||
| Cisco 8804 | ||
| Cisco 8808 | ||
| Cisco 8812 | ||
| Cisco 8818 |
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Reference Links
Frequently Asked Questions
What is the vulnerability ID?
The vulnerability ID is CVE-2021-34720.
What is the severity of CVE-2021-34720?
The severity of CVE-2021-34720 is high (8.6).
What software is affected by CVE-2021-34720?
Cisco IOS XR Software versions 6.2.3 to 6.3.2 and 6.5.0 to 7.2.2 are affected by CVE-2021-34720.
How can an attacker exploit CVE-2021-34720?
An attacker can exploit CVE-2021-34720 by sending specially crafted packets to the IP SLA responder or TWAMP features of Cisco IOS XR Software.
Is there a fix for CVE-2021-34720?
Yes, Cisco has released software updates to address the vulnerability. Please refer to the Cisco security advisory for more information.
- collector/nvd-index
- agent/references
- agent/severity
- agent/author
- agent/weakness
- agent/description
- agent/tags
- agent/type
- agent/event
- vendor/cisco
- canonical/cisco ios xr
- version/cisco ios xr/6.3.0
- version/cisco ios xr/6.5.0
- canonical/cisco asr 9000v-v2
- canonical/cisco asr 9001
- canonical/cisco asr 9006
- canonical/cisco asr 9010
- canonical/cisco asr 9901
- canonical/cisco asr 9902
- canonical/cisco asr 9903
- canonical/cisco asr 9904
- canonical/cisco asr 9906
- canonical/cisco asr 9910
- canonical/cisco asr 9912
- canonical/cisco asr 9922
- canonical/cisco ios xrv
- canonical/cisco ios xrv 9000
- canonical/cisco ncs 520
- canonical/cisco ncs 540
- canonical/cisco ncs 540 fronthaul
- canonical/cisco ncs 560-4
- canonical/cisco ncs 560-7
- canonical/cisco ncs 5001
- canonical/cisco ncs 5002
- canonical/cisco ncs 5011
- canonical/cisco ncs 4009
- canonical/cisco ncs 4016
- canonical/cisco ncs 5501
- canonical/cisco ncs 5501-se
- canonical/cisco ncs 5502
- canonical/cisco ncs 5502-se
- canonical/cisco ncs 5508
- canonical/cisco ncs 5516
- canonical/cisco ncs 6000
- canonical/cisco ncs 6008
- canonical/cisco ncs 1001
- canonical/cisco ncs 1002
- canonical/cisco ncs 1004
- canonical/cisco 8101-32fh
- canonical/cisco 8101-32h
- canonical/cisco 8102-64h
- canonical/cisco 8201
- canonical/cisco 8201-32fh
- canonical/cisco 8202
- canonical/cisco 8804
- canonical/cisco 8808
- canonical/cisco 8812
- canonical/cisco 8818