CVE-2021-22161 json
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…
published 2021-02-07 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-9307
- cvss
- 6.5
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.5%
- EPSS 0.5% chance of exploitation in 30 days, percentile 45%
- public exploits
- 0
- none known
Summary
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.
Exploit prediction
0.53% chance of exploitation in the next 30 days, higher than 45% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 6.5 | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVD | 2.0 | 3.3 | AV:A/AC:L/Au:N/C:N/I:N/A:P |
Classification
- Weakness
-
- CWE-835 Loop with Unreachable Exit Condition
References
-
openwrt.org
/advisory/2021-02-02-1
vendor-advisory
Sources
- CVE List CVE-2021-22161
- NVD CVE-2021-22161
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