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Vulnerability record · CVE-2021-27710 · published 14 April 2021

CVE-2021-27710: Totolink x5000r firmware os command injection vulnerability

TTotolink · X5000r Firmware

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, "ip" parameter is directly passed to the attacker, allowing them to control the "ip" field to attack the OS.

9.8 CVSS 3.1 Critical EPSS 7.9% · top 5.5% CWE-78 · OS command injection
9.8CVSS 3.1 base score, v2 10.0
7.9%EPSS exploitation probability, 30 days
NoNot in CISA KEV
2Affected product versions listed by NVD
4References, 4 tagged exploit
17 Jun 2026Last modified by NVD

Description

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, "ip" parameter is directly passed to the attacker, allowing them to control the "ip" field to attack the OS.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

2 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://hackmd.io/Hy3oVgtcQiuqAtv9FdylHw ExploitThird Party Advisory
https://hackmd.io/KjXzQdjDRjOuRjoZZXQo_A ExploitThird Party Advisory
https://hackmd.io/Hy3oVgtcQiuqAtv9FdylHw ExploitThird Party Advisory
https://hackmd.io/KjXzQdjDRjOuRjoZZXQo_A ExploitThird Party Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2025-70327Totolink x5000r firmware argument injection vulnerabilityTOTOLINK X5000R v9.1.0cu_2415_B20250515 contains an argument injection vulnerability in the setDiagnosisCfg handler of the /usr/sbin/lighttpd executa…EPSS 0.72%9.8CVE-2025-13184Totolink x5000r firmware incorrect authorization vulnerabilityUnauthenticated Telnet enablement via cstecgi.cgi (auth bypass) leading to unauthenticated root login with a blank password on factory/reset X5000R V…EPSS 11%9.8CVE-2024-32353Totolink x5000r firmware command injection vulnerabilityTOTOLINK X5000R V9.1.0cu.2350_B20230313 was discovered to contain a command injection vulnerability via the 'port' parameter in the setSSServer funct…EPSS 2.1%9.8CVE-2024-28639Totolink x5000r firmware classic buffer overflow vulnerabilityBuffer Overflow vulnerability in TOTOLink X5000R V9.1.0u.6118-B20201102 and A7000R V9.1.0u.6115-B20201022, allow remote attackers to execute arbitrar…EPSS 1.2%9.8CVE-2023-6612Totolink x5000r firmware os command injection vulnerabilityA vulnerability was found in Totolink X5000R 9.1.0cu.2300_B20230112. It has been rated as critical. This issue affects the function setDdnsCfg/setDyn…EPSS 31%9.8CVE-2023-45984Totolink x5000r firmware out-of-bounds write vulnerabilityTOTOLINK X5000R V9.1.0u.6118_B20201102 and TOTOLINK A7000R V9.1.0u.6115_B20201022 was discovered to contain a stack overflow via the lang parameter i…EPSS 0.70%9.8CVE-2023-36950Totolink x5000r firmware out-of-bounds write vulnerabilityTOTOLINK X5000R V9.1.0u.6118_B20201102 and TOTOLINK A7000R V9.1.0u.6115_B20201022 was discovered to contain a stack overflow via the http_host parame…EPSS 0.82%9.8CVE-2023-36947Totolink x5000r firmware out-of-bounds write vulnerabilityTOTOLINK X5000R V9.1.0u.6118_B20201102 and TOTOLINK A7000R V9.1.0u.6115_B20201022 was discovered to contain a stack overflow via the File parameter i…EPSS 0.82%

Source: NIST National Vulnerability Database (record CVE-2021-27710), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.