RCE in Totolink A720r

CVE-2021-27708

Command Injection in TOTOLINK X5000R router with firmware v9.1.0u.6118_B20201102, and TOTOLINK A720R router with firmware v4.1.5cu.470_B20200911 allows remote attackers to execute arbitrary OS commands by sending a modified HTTP request. This occurs because the function executes glibc's system function with untrusted input. In the function, "command" parameter is directly passed to the attacker, allowing them to control the "command" field to attack the OS.

Vulnerability class: Command Injection (OS Command Injection)

EPSS: 0.076 (93.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-27708?
CVE-2021-27708 is a critical-severity vulnerability in Totolink A720r, classified under OS Command Injection. CVSS score: 9.8/10. Published 2021-04-14.
How severe is CVE-2021-27708?
Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2021-27708 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.