CVE-2021-20856 Cross-site scripting in ELECOM LAN routers
Remote authenticated attackers can inject arbitrary scripts into ELECOM LAN routers, potentially compromising user sessions or device integrity.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2021-20856?
CVE-2021-20856 is a medium-severity cross-site scripting vulnerability in ELECOM LAN routers, published on 1 Dec 2021. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
Cross-site scripting vulnerability in ELECOM LAN routers (WRH-733GBK firmware v1.02.9 and prior and WRH-733GWH firmware v1.02.9 and prior) allows a remote authenticated attacker to inject an arbitrary script via unspecified vectors.
Weakness: CWE-79
Which versions are affected by CVE-2021-20856?
It affects 2 products.
Products include Elecom Wrh-733gbk Firmware, Elecom Wrh-733gwh Firmware.
How do I fix CVE-2021-20856?
No fix has been published for CVE-2021-20856 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2021-20856 being exploited?
There is no known exploitation of CVE-2021-20856 in the wild and no public exploit code.
Other vulnerabilities in ELECOM LAN routers
Sources
Also known as GHSA-r2j8-fmw2-73rf.