Raw vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:HSummary
CVE-2025-11847 is a medium-severity NULL Pointer Dereference (CWE-476) vulnerability in Zyxel Px3321-T1 Firmware. Its CVSS base score is 4.9 (Medium).
Operationally, ranked in the top 25% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and SI-11 (Error Handling) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-207553
Vulnerability Data
A null pointer dereference vulnerability in the IP settings CGI program of the Zyxel VMG3625-T50B firmware versions through 5.50(ABPM.9.6)C0 and the Zyxel WX3100-T0 firmware versions through 5.50(ABVL.4.8)C0 could allow an authenticated attacker with administrator privileges to trigger a denial-of-service (DoS)…
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condition by sending a crafted HTTP request.
- CWE(s)
Related Threats
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
Mitigating Controls (NIST 800-53 r5) AI
Requires validation of all inputs to the IP settings CGI so that crafted HTTP requests cannot reach the null-pointer code path.
Mandates graceful error handling that prevents a null dereference from terminating the web process and causing DoS.
Requires prompt application of firmware patches that eliminate the null-pointer flaw in the affected CGI.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices (static analysis, code review, safe coding standards) directly prevent NULL dereference bugs during development.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing can detect NULL dereference defects before release.
Secure SDLC mandates defensive coding practices that can prevent NULL dereferences.
Application security requirements can specify input validation and pointer-safety rules.
Secure architecture principles encourage defensive design that avoids unsafe pointer use.
Secure coding standards directly require NULL-pointer checks and safe dereference patterns.