Medium severity · published Feb 7, 2021
CVE-2021-22161
In OpenWrt 19.07.x before 19.07.7, when IPv6 is used, a routing loop can occur that generates excessive network traffic between an affected device and its upstream ISP's router
6.5
CVSS
0.5%
EPSS
No
On KEV
Description
In OpenWrt 19.07.x before 19.07.7, when IPv6 is used, a routing loop can occur that generates excessive network traffic between an affected device and its upstream ISP's router. This occurs when a link prefix route points to a point-to-point link, a destination IPv6 address belongs to the prefix and is not a local IPv6 address, and a router advertisement is received with at least one global unique IPv6 prefix for which the on-link flag is set. This affects the netifd and odhcp6c packages.
CVSS vector
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Adjacent
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 44% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
OP
Openwrt · Openwrt
19.07.0 through 19.07.6 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-22161
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-22161
Vendor Advisory
https://openwrt.org/advisory/2021-02-02-1
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