CVE-2012-10039: ZEN Load Balancer Filelog Command Execution

Severity: critical (CVSS 9.4 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 3.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-08-11 · updated 2026-06-16
Weakness: CWE-78

Description

ZEN Load Balancer versions 2.0 and 3.0-rc1 contain a command injection vulnerability in content2-2.cgi. The filelog parameter is passed directly into a backtick-delimited exec() call without sanitation. An authenticated attacker can inject arbitrary shell commands, resulting in remote code execution as the root user. ZEN Load Balancer is the predecessor of ZEVENET and SKUDONET. The affected versions (2.0 and 3.0-rc1) are no longer supported. SKUDONET CE is the current community-maintained successor.

Affected products

ZEN Load Balancer: 2.0, 3.0-rc1

References

https://raw.githubusercontent.com/rapid7/metasploit-framework/master/modules/exploits/linux/http/zen_load_balancer_exec.rb
https://web.archive.org/web/20111015031540/http://www.zenloadbalancer.com/
https://web.archive.org/web/20221203195056/https://itsecuritysolutions.org/2012-09-21-ZEN-Load-Balancer-v2.0-and-v3.0-rc1-multiple-vulnerabilities/
https://www.exploit-db.com/exploits/21849
https://www.fortiguard.com/encyclopedia/ips/33335/zen-load-balancer-filelog-command-execution

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