CVE-2023-43755

Deeper analysis

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 overflow vulnerabilities. The flaws occur when the devices parse certain fields within XML elements received over the network, because the firmware fails to validate that data against the allocated buffer size, resulting in out-of-bounds writes as described by CWE-121 and CWE-787.

An unauthenticated attacker with network access can send specially crafted XML requests to trigger the overflows. Successful exploitation yields remote code execution with the ability to read, modify, or delete data and fully compromise the affected camera, consistent with the CVSS 9.8 rating that reflects no required authentication or user interaction.

CISA has published ICS advisory ICSA-23-304-03 that addresses the vulnerabilities in these 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 0.0079, indicating a period of substantially increased exploitation interest after disclosure.