cbcvebase.
CVE-2020-15568
published 2021-01-30

CVE-2020-15568: TerraMaster TOS before 4.1.29 has Invalid Parameter Checking that leads to code injection as root. This is a dynamic class method invocation vulnerability in…

PriorityP187critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
ITWEXPLOITVulnCheck KEVInitial access
Exploited in the wild
EPSS
28.49%
97.9th percentile
TerraMaster TOS before 4.1.29 has Invalid Parameter Checking that leads to code injection as root. This is a dynamic class method invocation vulnerability in include/exportUser.php, in which an attacker can trigger a call to the exec method with (for example) OS commands in the opt parameter.

Affected

1 ranges
VendorProductVersion rangeFixed in
terra-mastertos< 4.1.294.1.29

Detection & IOCsextracted from sources · hover to see the quote

path/include/exportUser.php
url/include/exportUser.php?type=3&cla=application&func=_exec&opt=(cat%20/etc/passwd)%3E{{filename}}.txt
commandtype=3&cla=application&func=_exec&opt=<OS_COMMAND>
  • Look for GET requests to /include/exportUser.php with query parameters 'cla=application', 'func=_exec', and a non-empty 'opt' parameter — this is the exploit path for dynamic class method invocation leading to RCE as root.
  • Validate HTTP responses from /include/exportUser.php for content matching 'root:.*:0:0:' (passwd file output), indicating successful OS command injection.
  • Monitor for unauthenticated access to /include/exportUser.php from external IPs; the vulnerability requires no authentication (PR:N, UI:N per CVSS).
  • Attacker-created output files (e.g., random 4-char alpha .txt files) under /include/ on the TerraMaster device may indicate post-exploitation artifact staging.
  • ·The exploit targets TerraMaster TOS versions strictly before 4.1.29; devices running 4.1.29 or later are not affected.
  • ·The Nuclei template uses a randomised 4-character lowercase alpha filename as the output artifact; detection rules based on a fixed filename will miss real-world exploitation.
  • ·FOFA fingerprinting query used to identify exposed TerraMaster devices is '"terramaster" && header="tos"', which can help scope detection to relevant assets.

CVSS provenance

nvdv3.19.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
nvdv2.010.0CRITICALAV:N/AC:L/Au:N/C:C/I:C/A:C
vulncheck9.8CRITICAL
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