Cyber Resilience

CVE-2023-39435

Memory Safety in Zavio Cf7500 Firmware m2.1.6.05

Published
08 November 2023
Modified
21 November 2024
CVSS Score v3.1 8.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.012 66th percentile
Risk Priority 87 floored blend · peak EPSS

Summary

CVE-2023-39435 is a high-severity Stack-based Buffer Overflow (CWE-121) vulnerability in Zavio Cf7500 Firmware. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 34% 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 M2.1.6.05 contain a stack-based buffer overflow vulnerability. The flaw occurs when the devices process incoming network requests to update certain settings without properly validating or enforcing allocated buffer sizes, which can result in memory corruption. The issue is tracked under CWE-121 and CWE-787 and carries a CVSS 3.1 score of 8.8.

An attacker with low-privileged network access can send crafted requests that trigger the overflow, enabling remote code execution on the affected camera with impacts to confidentiality, integrity, and availability. No user interaction is required and the attack can be launched over the network.

CISA has published ICS advisory ICSA-23-304-03 addressing the affected Zavio devices. The EPSS score for this CVE rose sharply from a low baseline to a peak of 0.5954 on 2025-01-22 before receding to the current value of 0.0034, indicating a period of increased exploitation interest after disclosure.

EU & UK References

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 stack-based overflows. During the process of updating certain settings sent from incoming network requests, the product does not…

more

sufficiently check or validate allocated buffer size. This may lead to remote code execution.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
T1211 Exploitation for Stealth Stealth
Adversaries may exploit vulnerabilities to evade detection by hiding activity, suppressing logging, or operating within trusted or unmonitored components.
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-45225Same product: Zavio B8220
CVE-2023-3959Same product: Zavio B8220
CVE-2023-43755Same product: Zavio B8220
CVE-2023-4249Same product: Zavio B8220
CVE-2023-4756Shared CWE-121, CWE-787
CVE-2024-4494Shared CWE-121, CWE-787
CVE-2024-4236Shared CWE-121, CWE-787
CVE-2024-4118Shared CWE-121, CWE-787
CVE-2025-29840Shared CWE-121, CWE-787
CVE-2023-25085Shared CWE-121, CWE-787

Affected Assets

zavio
cf7500 firmware
m2.1.6.05
zavio
cf7300 firmware
m2.1.6.05
zavio
cf7201 firmware
m2.1.6.05
zavio
cf7501 firmware
m2.1.6.05
zavio
cb3211 firmware
m2.1.6.05
zavio
cb3212 firmware
m2.1.6.05
zavio
cb5220 firmware
m2.1.6.05
zavio
cb6231 firmware
m2.1.6.05
zavio
b8520 firmware
m2.1.6.05
zavio
b8220 firmware
m2.1.6.05
+1 more product configuration(s) — see NVD for full list

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 2 hardening rules · 2 OS baselines
Validate
Prove the fix (OWASP ASVS)

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.

addresses: CWE-787

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.

PR.PS-06 mostly match
prevents

Secure-development practices directly prevent introduction of stack buffer overflows.

ID.RA-01 partial match
prevents

Vulnerability scanning can discover stack buffer overflows but does not prevent their introduction.

PR.PS-02 partial match
prevents

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.

finds

Security testing (fuzzing, static analysis) detects stack overflows before release.

prevents

Secure SDLC mandates buffer-safety practices that directly prevent stack overflows.

prevents

Application security requirements can specify buffer-size and input-validation rules.

prevents

Secure architecture principles include memory-safety and least-privilege stack usage.

prevents

Secure coding standards explicitly forbid unsafe buffer handling that causes CWE-121.

prevents

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

References