Vulnerability · Published Dec 30, 2021 · Assigned by tenable

CVE-2021-20134

High 8.4

In plain English

A high-severity security flaw in Quagga Services on D-Link DIR-2640 Routers. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 7.8% (higher than 95% of all known vulnerabilities).

Severity (CVSS NVD)8.4High

Exploit odds (30 days)7.8%top 5.3% of all CVEs

Exploited in the wildNo reportsnot in CISA KEV

Attack toolingNoneno public tooling known

Official description

Quagga Services on D-Link DIR-2640 less than or equal to version 1.11B02 are affected by an absolute path traversal vulnerability that allows a remote, authenticated attacker to set an arbitrary file on the router's filesystem as the log file used by either Quagga service (zebra or ripd). Subsequent log messages will be appended to the file, prefixed by a timestamp and some logging metadata. Remote code execution can be achieved by using this vulnerability to append to a shell script on the router's filesystem, and then awaiting or triggering the execution of that script. A remote, unauthenticated root shell can easily be obtained on the device in this fashion.

Affected products (as reported)

Vendor	Product	Versions
n/a	Quagga Services on D-Link DIR-2640 Routers	<= 1.11B02

References

https://www.tenable.com/security/research/tra-2021-44 x_refsource_MISC