CVE-2026-23759: CWE-78 Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') in Perle Systems IOLAN STS
Perle IOLAN STS/SCS terminal server models with firmware versions prior to 6.0 allow authenticated OS command injection via the restricted shell accessed over Telnet or SSH. The shell 'ps' command does not perform proper argument sanitization and passes user-supplied parameters into an 'sh -c' invocation running as root. An authenticated attacker who can log in to the device can inject shell metacharacters after the 'ps' subcommand to execute arbitrary OS commands with root privileges, leading to full compromise of the underlying operating system.
AI Analysis
Technical Summary
CVE-2026-23759 is an OS command injection vulnerability in Perle Systems IOLAN STS terminal servers running firmware versions before 6.0. The restricted shell's 'ps' command fails to properly neutralize special characters in user-supplied arguments, passing them directly into a root-level 'sh -c' invocation. An authenticated attacker with shell access over Telnet or SSH can exploit this to execute arbitrary OS commands with root privileges, resulting in full system compromise.
Potential Impact
An attacker with valid credentials can gain root-level command execution on affected devices, leading to complete control over the operating system. This could allow 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 access to the device's Telnet and SSH interfaces to trusted users only and monitor for unauthorized access attempts. Avoid using firmware versions prior to 6.0 where possible.
CVE-2026-23759: CWE-78 Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') in Perle Systems IOLAN STS
Description
Perle IOLAN STS/SCS terminal server models with firmware versions prior to 6.0 allow authenticated OS command injection via the restricted shell accessed over Telnet or SSH. The shell 'ps' command does not perform proper argument sanitization and passes user-supplied parameters into an 'sh -c' invocation running as root. An authenticated attacker who can log in to the device can inject shell metacharacters after the 'ps' subcommand to execute arbitrary OS commands with root privileges, leading to full compromise of the underlying operating system.
CVSS v4.0
Score 8.6high
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-23759 is an OS command injection vulnerability in Perle Systems IOLAN STS terminal servers running firmware versions before 6.0. The restricted shell's 'ps' command fails to properly neutralize special characters in user-supplied arguments, passing them directly into a root-level 'sh -c' invocation. An authenticated attacker with shell access over Telnet or SSH can exploit this to execute arbitrary OS commands with root privileges, resulting in full system compromise.
Potential Impact
An attacker with valid credentials can gain root-level command execution on affected devices, leading to complete control over the operating system. This could allow 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 access to the device's Telnet and SSH interfaces to trusted users only and monitor for unauthorized access attempts. Avoid using firmware versions prior to 6.0 where possible.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-01-15T18:42:20.938Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 69b99a3b771bdb1749cb0c80
Added to database: 3/17/2026, 6:15:23 PM
Last enriched: 5/14/2026, 2:08:51 AM
Last updated: 6/15/2026, 8:45:56 PM
Views: 134
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