Zyxel DSL CPE OS Command Injection Vulnerability
Zyxel · DSL CPE Devices
A command injection flaw in the CGI program of Zyxel DSL CPE Devices (the legacy VMG4325-B10A, firmware 1.00(AAFR.4)C0_20170615) lets an attacker run operating system commands on the affected device. Exploitation requires an authenticated session and a crafted HTTP POST request sent to the device, with no user interaction needed.
**UNSUPPORTED WHEN ASSIGNED** A post-authentication command injection vulnerability in the CGI program of the legacy DSL CPE Zyxel VMG4325-B10A firmware version 1.00(AAFR.4)C0_20170615 could allow an authenticated attacker to execute operating system (OS) commands on an affected device by sending a crafted HTTP POST request.
- Exploited
- Yes, in CISA KEV
- Reports
- 0
- Tactics
- 3/15
How an attack unfolds
Based on MITRE ATT&CKA public catalogue of the techniques attackers use, maintained by MITRE. Patchfirst uses it to describe what attackers do with a vulnerability. mappings. Select a step to see the evidence.Exploitation timelineDated milestones for a CVE: when it was disclosed, when exploit code became public, when exploitation was confirmed, and when threat reports named it.
First seen exploited 7 days before it was disclosed.
- First seen exploitedVulnCheck KEV evidence7 days before
- Disclosedday 0
- Added to CISA KEVEU database agrees+7 days
CISA KEV listing is when exploitation was confirmed, not necessarily the first attack.
MITRE ATT&CKA public catalogue of the techniques attackers use, maintained by MITRE. Patchfirst uses it to describe what attackers do with a vulnerability. techniques
2 TechniqueOne specific attacker behaviour in MITRE ATT&CK, such as T1190 “Exploit Public-Facing Application”. IDs with a dot, like T1059.004, are sub-techniques., grouped by TacticThe attacker’s goal at a stage of an attack in MITRE ATT&CK, such as Initial Access or Persistence. Each technique belongs to one or more tactics. in kill-chain order 2Privilege EscalationTA0004
Zyxel CPE contain an HTTP-based vulnerability that facilitates code execution that can lead to data exfiltration, network infiltration, and total system compromise. No public proof-of-concept exists for this exploit, and Zyxel has no intention of patching the vulnerability since the devices affected are end-of-life.
ExfiltrationTA0010
Detection
0 rules for this CVE · 37 general rules for its techniquesRules for this CVE
0Sigma ruleAn open, vendor-neutral detection rule for log data. Security teams convert Sigma rules into searches for their own SIEM. that reference CVE-2024-40890 directly.CVE-specific rules are not available in this build. Search SigmaHQ ↗
General rules for this CVE’s techniques
These detect the technique in general, not this specific vulnerability.
Process InjectionT105537 general rules
- Antivirus PrinterNightmare CVE-2021-34527 Exploit Detectioncriticalstable
- Potential Dridex Activitycriticalstable
- CobaltStrike Named Pipecriticaltest
- CobaltStrike Named Pipe Pattern Regexcriticaltest
- HackTool - DInjector PowerShell Cradle Executioncriticaltest
- Malicious Named Pipe Createdcriticaltest
- RedSun - Named Pipe Createdcriticalexperimental
- RedSun - TieringEngineService.exe Detected as EICAR Test Filecriticalexperimental
Sigma rules © SigmaHQ, Detection Rule License 1.1; linked, not reproduced.
What security researchers reported
Not named in any threat report yetAlso mentioned in 50 community threat pulses (AlienVault OTX)
Weaker evidencePulses are indicator collections that anyone can publish. A mention is not confirmation of exploitation.
- Actively_Exploited_Kev | Oct 30, 202629 Oct 2026
- Actively_Exploited_Kev | Oct 29, 202628 Oct 2026
- Actively_Exploited_Kev | Oct 28, 202627 Oct 2026
- Actively_Exploited_Kev | Oct 27, 202626 Oct 2026
- Actively_Exploited_Kev | Oct 24, 202623 Oct 2026
- Actively_Exploited_Kev | Oct 23, 202622 Oct 2026
- 44 more on OTX