CVE intelligence and bounded remediation

CVE-2021-29508 — Due to how Wire handles type information in its serialization format, malicious payloads can be passed to a deserializer

Critical CVSS 9.1

Due to how Wire handles type information in its serialization format, malicious payloads can be passed to a deserializer. e.g. using a surrogate on the sender end, an attacker can pass information about a different type for the receiving end. And by doing so allowing the serializer to create any type on the deserializing end. This is the same issue that exists for .NET BinaryFormatter https://docs.microsoft.com/en-us/visualstudio/code-quality/ca2300?view=vs-2019. This also applies to the fork of Wire.

Severity
Critical
CVSS
9.1 (3.1)
Published
2021-05-11
CISA KEV
Not currently listed
Ecosystem
windows/system
Weaknesses
CWE-502

Affected products

  • asynkron / wire

Matched remediation archetype

Unsafe deserialization and object reconstruction

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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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