CVE-2026-71921: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') in DrayTek Corporation VigorSwitch G2540xs
CVE-2026-71921 is a critical pre-authentication OS command injection vulnerability in DrayTek VigorSwitch G2540xs devices. It exists in the setget.cgi interface due to insufficient filtering of the 'pass' field, allowing remote attackers to execute arbitrary commands with root privileges without authentication.
AI Analysis
Technical Summary
This vulnerability affects multiple DrayTek VigorSwitch models, specifically the G2540xs, where the setget.cgi interface improperly neutralizes special elements in the 'pass' parameter before command execution. This flaw enables a remote attacker to inject OS commands that execute with root privileges, bypassing authentication controls. The CVSS 4.0 score of 9.3 reflects its critical severity, with network attack vector, no required privileges, no user interaction, and high impact on confidentiality, integrity, and availability.
Potential Impact
Successful exploitation allows remote attackers to execute arbitrary OS commands with root privileges on affected devices without any authentication. This can lead to full system compromise, unauthorized access, data manipulation, or disruption of device functionality.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, restrict network access to the management interface and monitor for suspicious activity related to the setget.cgi interface.
CVE-2026-71921: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') in DrayTek Corporation VigorSwitch G2540xs
Description
CVE-2026-71921 is a critical pre-authentication OS command injection vulnerability in DrayTek VigorSwitch G2540xs devices. It exists in the setget.cgi interface due to insufficient filtering of the 'pass' field, allowing remote attackers to execute arbitrary commands with root privileges without authentication.
CVSS v4.0
Score 9.3critical
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability affects multiple DrayTek VigorSwitch models, specifically the G2540xs, where the setget.cgi interface improperly neutralizes special elements in the 'pass' parameter before command execution. This flaw enables a remote attacker to inject OS commands that execute with root privileges, bypassing authentication controls. The CVSS 4.0 score of 9.3 reflects its critical severity, with network attack vector, no required privileges, no user interaction, and high impact on confidentiality, integrity, and availability.
Potential Impact
Successful exploitation allows remote attackers to execute arbitrary OS commands with root privileges on affected devices without any authentication. This can lead to full system compromise, unauthorized access, data manipulation, or disruption of device functionality.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, restrict network access to the management interface and monitor for suspicious activity related to the setget.cgi interface.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-08-08T16:37:44.518Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a8c7de9acd9273b49e1b371
Added to database: 08/24/2026, 17:22:49 UTC
Last enriched: 08/24/2026, 17:39:18 UTC
Last updated: 08/24/2026, 19:39:38 UTC
Views: 4
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