CVE-2021-22161 Denial of service in n/a
An attacker can trigger a routing loop in OpenWrt devices using IPv6, causing excessive network traffic and potential service disruption.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-22161?
CVE-2021-22161 is a medium-severity denial of service vulnerability in Openwrt Openwrt, published on 7 Feb 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Weakness: CWE-835
Which versions are affected by CVE-2021-22161?
It affects 1 product.
Products include Openwrt Openwrt.
How do I fix CVE-2021-22161?
No fix has been published for CVE-2021-22161 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2021-22161 being exploited?
There is no known exploitation of CVE-2021-22161 in the wild and no public exploit code.
Other vulnerabilities in Openwrt Openwrt
- CVE-2020-28951 Use after free in n/a
- CVE-2026-62948 Cross-site scripting in openwrt
- CVE-2026-30871 OpenWrt Project has Stack-based Buffer Overflow in DNS PTR Query
- CVE-2026-30872 OpenWrt Project has a Stack-based Buffer Overflow vulnerability via IPv6 reverse DNS lookup
- CVE-2021-28961 Command injection in n/a
Sources
Also known as GHSA-jw75-vvj8-5h3f.