CVE intelligence and bounded remediation

CVE-2020-6959 — Honeywell Maxpro Nvr Xe Firmware security vulnerability

Critical CVSS 9.8

The following versions of MAXPRO VMS and NVR, MAXPRO VMS:HNMSWVMS prior to Version VMS560 Build 595 T2-Patch, HNMSWVMSLT prior to Version VMS560 Build 595 T2-Patch, MAXPRO NVR: MAXPRO NVR XE prior to Version NVR 5.6 Build 595 T2-Patch, MAXPRO NVR SE prior to Version NVR 5.6 Build 595 T2-Patch, MAXPRO NVR PE prior to Version NVR 5.6 Build 595 T2-Patch, and MPNVRSWXX prior to Version NVR 5.6 Build 595 T2-Patch are vulnerable to an unsafe deserialization of untrusted data. An attacker may be able to remotely modify deserialized data without authentication using a specially crafted web request, resulting in remote code execution.

Severity
Critical
CVSS
9.8 (3.1)
Published
2020-01-22
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-502

Affected products

  • honeywell / maxpro_nvr_xe_firmware
  • honeywell / maxpro_nvr_se_firmware
  • honeywell / maxpro_nvr_pe_firmware
  • honeywell / mpnvrswxx_firmware
  • honeywell / hnmswvms_firmware
  • honeywell / hnmswvmslt_firmware

Matched remediation archetype

Unsafe deserialization and object reconstruction

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Inventory serialization formats accepted from requests, queues, caches, files, cookies, and cross-service messages.
  • Trace whether untrusted input can select classes, types, callbacks, constructors, or object hooks during decoding.
  • Identify signing, schema validation, trust-boundary, and compatibility settings for each decoder.

Remediate safely

  • Replace native object deserialization with a data-only format and explicit schema validation.
  • If replacement is not immediate, use a safe decoder with a minimal type allowlist and disable polymorphic or executable hooks.
  • Update the affected library and add inert tests for unknown types, extra fields, malformed nesting, and unsigned data.

Authoritative sources

Complete CVE record and remediation plan

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