CVE-2021-34737 (GCVE-0-2021-34737)
Vulnerability from cvelistv5 – Published: 2021-09-09 05:01 – Updated: 2024-11-07 22:00
VLAI
EPSS
VEX
Title
Cisco IOS XR Software DHCP Version 4 Server Denial of Service Vulnerability
Summary
A vulnerability in the DHCP version 4 (DHCPv4) server feature of Cisco IOS XR Software could allow an unauthenticated, remote attacker to trigger a crash of the dhcpd process, resulting in a denial of service (DoS) condition. This vulnerability exists because certain DHCPv4 messages are improperly validated when they are processed by an affected device. An attacker could exploit this vulnerability by sending a malformed DHCPv4 message to an affected device. A successful exploit could allow the attacker to cause a NULL pointer dereference, resulting in a crash of the dhcpd process. While the dhcpd process is restarting, which may take up to approximately two minutes, DHCPv4 server services are unavailable on the affected device. This could temporarily prevent network access to clients that join the network during that time period. Note: Only the dhcpd process crashes and eventually restarts automatically. The router does not reload.
Severity
5.8 (Medium)
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2024-11-07 21:54 UTC
CWE
Assigner
cisco
CNA
References
1 reference
| URL | Tags |
|---|---|
| https://tools.cisco.com/security/center/content/C… | vendor-advisoryx_refsource_CISCO |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Cisco | Cisco IOS XR Software |
Affected:
n/a
|
Date Public
2021-09-08 00:00
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Sightings
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Nomenclature
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Browse all ATT&CK techniques and the vulnerabilities related to each.
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