cbcvebase.
CVE-2023-34992
published 2023-10-10

CVE-2023-34992: A improper neutralization of special elements used in an os command ('os command injection') vulnerability in Fortinet allows attacker to execute unauthorized…

PriorityP182critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
EPSS
65.51%
99.2th percentile
A improper neutralization of special elements used in an os command ('os command injection') vulnerability in Fortinet allows attacker to execute unauthorized code or commands via crafted API requests.

Affected

12 ranges
VendorProductVersion rangeFixed in
fortinetfortinet
fortinetfortisiem
fortinetfortisiem
fortinetfortisiem
fortinetfortisiem
fortinetfortisiem
fortinetfortisiem
fortinetfortisiem
fortinetfortisiem6.4.0 – 6.4.2
fortinetfortisiem6.5.0 – 6.5.1
fortinetfortisiem6.6.0 – 6.6.3
fortinetfortisiem6.7.0 – 6.7.5

Detection & IOCsextracted from sources · hover to see the quote

port7900
path/opt/phoenix/log/phoenix.logs
snort
alert tcp any any -> $HOME_NET 7900 (msg:"ET EXPLOIT Fortinet FortiSIEM Unauthenticated Command Injection CVE-2023-34992"; flow:established,to_server; content:"|51 00 00 00|"; startswith; content:"]*>[^\x3b/Rsi"; reference:url,horizon3.ai/attack-research/cve-2023-34992-fortinet-fortisiem-command-injection-deep-dive/; reference:cve,2023-34992; classtype:misc-attack; sid:2052888; rev:2; metadata:attack_target Server, created_at 2024_05_28, cve CVE_2023_34992, deployment Perimeter, deployment Internal, confidence High, signature_severity Major, tag Exploit, updated_at 2024_05_31, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application;)
bytes
|51 00 00 00|
  • Exploit traffic targets TCP port 7900 (phMonitor service) with a specific 4-byte little-endian length prefix |51 00 00 00| at the start of the TCP payload, followed by content matching the pattern ]*>[^\x3b/Rsi
  • Exploitation attempts against the patch bypass variant (CVE-2024-23108) leave a log message containing a failed command referencing 'datastore.py nfs test' — hunt for this string in FortiSIEM logs
  • For the related CVE-2025-64155 variant, check /opt/phoenix/log/phoenix.logs for 'PHL_ERROR' lines that include a payload URL and destination file path, indicating active exploitation of the phMonitor service
  • The vulnerability is exploited via crafted API requests to the FortiSIEM supervisor/report server; monitor for anomalous unauthenticated API calls to FortiSIEM endpoints
  • ·The phMonitor service (port 7900) exposes dozens of command handlers remotely without authentication and has been the entry point for multiple FortiSIEM CVEs; blocking or restricting access to this port is the vendor-recommended workaround when patching is not immediately possible
  • ·The patch for CVE-2023-34992 added wrapShellToken() to escape user-controlled inputs, but this was insufficient — a second-order command injection remained exploitable when certain parameters to datastore.py are sent
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