cbcvebase.
CVE-2024-29972
published 2024-06-04

CVE-2024-29972: ** UNSUPPORTED WHEN ASSIGNED ** The command injection vulnerability in the CGI program "remote_help-cgi" in Zyxel NAS326 firmware versions before…

PriorityP193critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
ITWEXPLOITVulnCheck KEVInitial access
Exploited in the wild
EPSS
89.22%
99.8th percentile
** UNSUPPORTED WHEN ASSIGNED **
The command injection vulnerability in the CGI program "remote_help-cgi" in Zyxel NAS326 firmware versions before V5.21(AAZF.17)C0 and NAS542 firmware versions before V5.21(ABAG.14)C0 could allow an unauthenticated attacker to execute some operating system (OS) commands by sending a crafted HTTP POST request.

Affected

4 ranges
VendorProductVersion rangeFixed in
zyxelnas326_firmware< V5.21(AAZF.17)C0V5.21(AAZF.17)C0
zyxelnas326_firmware< 5.21\(aazf.17\)c05.21\(aazf.17\)c0
zyxelnas542_firmware< V5.21(ABAG.14)C0V5.21(ABAG.14)C0
zyxelnas542_firmware< 5.21\(abag.14\)c05.21\(abag.14\)c0

Detection & IOCsextracted from sources · hover to see the quote

path/cgi-bin/remote_help-cgi/
url/desktop,/cgi-bin/remote_help-cgi/favicon.ico?type=sshd_tdc
otherNsaRescueAngel (backdoor account with root privileges)
snort
alert http any any -> $HOME_NET any (msg:"ET WEB_SPECIFIC_APPS Zyxel NAS CGI Command Injection (CVE-2024-29972)"; flow:established, to_server; http.method; content:"GET"; http.uri; content:"/cgi-bin/remote_help-cgi/"; content:"type=sshd_tdc"; fast_pattern; distance:0; reference:url,outpost24.com/blog/zyxel-nas-critical-vulnerabilities/; reference:cve,2024-29972; classtype:web-application-activity; sid:2055907; rev:1; metadata:affected_product Zyxel, tls_state plaintext, created_at 2024_09_18, cve CVE_2024_29972, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag Exploit, updated_at 2024_09_18, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application; target:dest_ip;)
  • Detect exploitation attempts by matching HTTP GET requests to the URI path '/cgi-bin/remote_help-cgi/' containing the query parameter 'type=sshd_tdc'.
  • A successful exploitation response will return HTTP 200 with the body containing 'result=0'.
  • The attack vector is an unauthenticated HTTP POST (or GET with crafted URI) request to the 'remote_help-cgi' CGI program; no authentication is required, making it detectable at the perimeter on plaintext HTTP traffic.
  • FOFA fingerprint query 'app="ZYXEL-NAS326"' can be used to identify exposed Zyxel NAS326 devices on the internet for proactive asset identification.
  • ·Both NAS326 and NAS542 are end-of-life products (support ended December 31, 2023); Zyxel issued emergency patches only for the three critical CVEs (CVE-2024-29972, -29973, -29974). Two other flaws (CVE-2024-29975, CVE-2024-29976) were NOT patched.
  • ·Public proof-of-concept (PoC) exploits are available, significantly raising the risk of in-the-wild exploitation even though Zyxel had not observed exploitation at time of disclosure.

CVSS provenance

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