CVE-2026-5176
Published: 31 March 2026
Summary
CVE-2026-5176 is a medium-severity Injection (CWE-74) vulnerability in Totolink A3300R Firmware. Its CVSS base score is 6.9 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 22.6% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified are NIST 800-53 SC-14 (Public Access Protections) and SI-10 (Information Input Validation).
Deeper analysis
A command injection vulnerability exists in the Totolink A3300R router running firmware version 17.0.0cu.557_b20221024. The flaw resides in the setSyslogCfg function of /cgi-bin/cstecgi.cgi and stems from insufficient validation of a supplied argument, allowing an attacker to inject and execute operating system commands.
An unauthenticated remote attacker can trigger the issue over the network without user interaction by submitting a crafted request to the CGI endpoint. Successful exploitation yields limited control over confidentiality, integrity, and availability on the device.
Public exploit code has been published. The associated EPSS score rose from a low baseline to a peak of 0.0486, indicating that exploitation interest increased after disclosure.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-17279
Vulnerability details
A security flaw has been discovered in Totolink A3300R 17.0.0cu.557_b20221024. Affected is the function setSyslogCfg of the file /cgi-bin/cstecgi.cgi. Performing a manipulation of the argument provided results in command injection. The attack may be initiated remotely. The exploit has been…
more
released to the public and may be used for attacks.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
The vulnerability is a command injection in a public-facing CGI web interface on a router, enabling unauthenticated remote exploitation (T1190) for arbitrary command execution akin to network device CLI abuse (T1059.008).
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Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly prevents command injection vulnerability by validating arguments provided to the setSyslogCfg function in cstecgi.cgi.
Requires timely identification, reporting, and correction of the specific command injection flaw through patching or firmware updates.
Enforces authorizations and security requirements on the publicly accessible vulnerable CGI endpoint to block unauthenticated remote exploitation.