Cyber Resilience

CVE-2021-27708

CriticalPublic PoCRCE

Published: 14 April 2021

Published
14 April 2021
Modified
21 November 2024
KEV Added
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Patch
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CVSS Score v3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.2015 95.6th percentile
Risk Priority 32 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-27708 is a critical-severity OS Command Injection (CWE-78) vulnerability in Totolink X5000R Firmware. Its CVSS base score is 9.8 (Critical).

Operationally, ranked in the top 4.4% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

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…

more

untrusted input. In the function, "command" parameter is directly passed to the attacker, allowing them to control the "command" field to attack the OS.

CWE(s)
CWE-78

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

totolink
x5000r firmware
9.1.0u.6118_b20201102
totolink
a720r firmware
4.1.5cu.470_b20200911

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

SC-27 Platform-independent Applications
addresses: CWE-78

Platform-independent apps typically execute inside a managed runtime or sandbox that restricts direct OS command execution, reducing the ability to exploit OS command injection.

SI-10 Information Input Validation
addresses: CWE-78

Validates inputs to block special elements that would alter OS command execution.

References