cbcvebase.
CVE-2020-13167
published 2020-05-19

CVE-2020-13167: Netsweeper through 6.4.3 allows unauthenticated remote code execution because webadmin/tools/unixlogin.php (with certain Referer headers) launches a command…

PriorityP191critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
ITWEXPLOITVulnCheck KEV
Exploited in the wild
EPSS
95.42%
99.9th percentile
Netsweeper through 6.4.3 allows unauthenticated remote code execution because webadmin/tools/unixlogin.php (with certain Referer headers) launches a command line with client-supplied parameters, and allows injection of shell metacharacters.

Affected

1 ranges
VendorProductVersion rangeFixed in
netsweepernetsweeper<= 6.4.3

Detection & IOCsextracted from sources · hover to see the quote

path/webadmin/tools/unixlogin.php
url/webadmin/tools/unixlogin.php?login=admin&password=g%27%2C%27%27%29%3Bimport%20os%3Bos.system%28%27{{url_encode(hex_encode(cmd))}}%27.decode%28%27hex%27%29%29%23&timeout=5
path/webadmin/out
path/usr/local/netsweeper/webadmin/out
otherReferer: {{BaseURL}}/webadmin/admin/service_manager_data.php
commandg',' ')%3Bimport os%3Bos.system('...'.decode('hex'))#
  • Exploit requests target /webadmin/tools/unixlogin.php with a crafted 'password' parameter containing Python injection payload (import os;os.system(...)) and a whitelisted Referer header pointing to /webadmin/admin/service_manager_data.php.
  • Look for HTTP GET requests to /webadmin/tools/unixlogin.php where the 'password' parameter contains URL-encoded Python metacharacters such as %3Bimport%20os%3Bos.system (';import os;os.system').
  • Post-exploitation artifact: a file written to /usr/local/netsweeper/webadmin/out can be used to confirm successful RCE; monitor for unexpected file creation in that path.
  • A follow-up GET to /webadmin/out returning HTTP 200 with attacker-controlled content confirms successful code execution; correlate the two requests in web logs.
  • The exploit runs as root on CentOS-based Netsweeper appliances; any suspicious process spawned by the web server (e.g., os.system calls) should be treated as high-severity.
  • ·Although the original advisory lists versions 6.4.3 and prior as vulnerable, version 6.4.4 has also been confirmed exploitable in testing.
  • ·The Referer header used for authentication bypass is described as 'random whitelisted', meaning multiple Referer values may be accepted; detections relying solely on a single Referer value may miss variants.

CVSS provenance

nvdv3.19.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
nvdv2.07.5HIGHAV:N/AC:L/Au:N/C:P/I:P/A:P
vulncheck9.8CRITICAL
CVEs like this are exactly what “Exploited This Week” covers.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.