CVE-2023-3959
Memory Safety in Zavio Cf7500 Firmware m2.1.6.05
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HSummary
CVE-2023-3959 is a critical-severity Stack-based Buffer Overflow (CWE-121) vulnerability in Zavio Cf7500 Firmware. Its CVSS base score is 9.8 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 1% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
Zavio IP cameras including the CF7500, CF7300, CF7201, CF7501, CB3211, CB3212, CB5220, CB6231, B8520, B8220, and CD321 models running firmware version M2.1.6.05 contain multiple stack-based buffer overflows. The flaws occur during processing of XML elements received over the network, where the firmware fails to validate buffer sizes before writing data, resulting in out-of-bounds writes as described by CWE-121 and CWE-787. The issues carry a CVSS 3.1 score of 9.8.
An unauthenticated attacker with network access can send specially crafted XML requests to trigger the overflows and achieve remote code execution on the affected cameras. No user interaction or credentials are required, and the attack can be performed remotely with low complexity.
CISA has published ICS advisory ICSA-23-304-03 detailing the affected devices and associated risks.
The EPSS score for this CVE rose from a low baseline to a peak of 0.5954 on 2025-01-22 before receding to its current value of 0.0050, indicating a period of increased exploitation interest well after initial disclosure.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-44584
Vulnerability Data
Zavio CF7500, CF7300, CF7201, CF7501, CB3211, CB3212, CB5220, CB6231, B8520, B8220, and CD321 IP Cameras with firmware version M2.1.6.05 are vulnerable to multiple instances of stack-based overflows. While processing XML elements from incoming network requests, the product does not sufficiently…
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check or validate allocated buffer size. This may lead to remote code execution.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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- 2 hardening rules · 2 OS baselines
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Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Out-of-bounds writes that corrupt control flow or inject shellcode are rendered non-executable by the same memory protections.
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-development practices directly prevent introduction of stack buffer overflows.
Vulnerability scanning can discover stack buffer overflows but does not prevent their introduction.
Patching eliminates known instances of the weakness after discovery.
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 (fuzzing, static analysis) detects stack overflows before release.
Secure SDLC mandates buffer-safety practices that directly prevent stack overflows.
Application security requirements can specify buffer-size and input-validation rules.
Secure architecture principles include memory-safety and least-privilege stack usage.
Secure coding standards explicitly forbid unsafe buffer handling that causes CWE-121.
Change management can enforce review gates that catch unsafe memory operations before deployment.
Hardening callouts derived
Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).
Oracle Linux 8 (1 rule)
- V-248594 OL 8 must implement address space layout randomization (ASLR) to protect its memory from unauthorized code execution. prevents CWE-121
Oracle Linux 9 (1 rule)
- V-271452 OL 9 must use a Linux Security Module configured to enforce limits on system services. prevents CWE-121