CVE-2026-48687
FastNetMon Community Edition through 1.2.9 contains an OS command injection vulnerability in the Juniper router integration plugin.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.65%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
FastNetMon Community Edition through 1.2.9 contains an OS command injection vulnerability in the Juniper router integration plugin. The _log() function in src/juniper_plugin/fastnetmon_juniper.php (lines 117-118) constructs shell commands by concatenating the $msg parameter directly into exec() calls: exec("echo `date` \"- {FASTNETMON] - " . $msg . " \" >> " . $FILE_LOG_TMP). The $msg variable contains unsanitized data derived from command-line arguments argv[1] through argv[3], which represent the attack IP address, direction, and power. While FastNetMon's C++ core currently passes IP addresses via inet_ntoa() (which only produces safe dotted-decimal notation), the PHP script performs no input validation or shell escaping. If the script is invoked directly, by another orchestration system, or if future code changes pass string-sourced IPs, arbitrary commands can be injected. The correct fix is to replace exec() with file_put_contents() or use escapeshellarg() on all parameters.
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 1.65% probability · 75th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-78
- Affected
- pavel-odintsov/fastnetmon
- Source
- cve@mitre.org
References
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.