Security readout for executives and security teams
Plain-English summary
CVE-2021-29508 is a critical insecure deserialization flaw in AsynkronIT Wire version 1.0.0 and earlier. If an application accepts untrusted Wire-serialized data, an attacker may cause the receiver to create unintended object types, threatening data integrity and service availability.
Executive priority
Treat this as urgent for internet-facing or partner-facing systems using Wire. The impact is not data theft by CVSS, but unauthorized object creation can compromise transaction integrity or disrupt service availability.
Technical view
Wire’s serialization format mishandles type information. A malicious sender can supply payloads that describe a different receiving-end type, including through surrogate behavior, allowing arbitrary type creation during deserialization. CVSS 3.1 is 9.1: network attack vector, low complexity, no privileges, no user interaction, high integrity and availability impact.
Likely exposure
Exposure is likely limited to .NET applications that use Wire or its fork to deserialize data from users, network peers, queues, files, caches, or other untrusted sources. Internal-only serialization paths reduce risk but should still be reviewed.
Exploitation context
The CVE is not listed as CISA KEV in the provided bundle, and no cited source states active exploitation. The risk is highest where deserialization is remotely reachable and processes attacker-controlled Wire payloads.
Researcher notes
The weakness maps to CWE-502 and resembles .NET BinaryFormatter-style deserialization risk. The provided sources identify affected Wire versions up to 1.0.0 and note the fork also applies, but do not provide deployment-specific exploit evidence.
Mitigation direction
- Inventory all applications and dependencies using Wire version 1.0.0 or earlier.
- Check the GitHub advisory and NuGet package guidance for fixed or supported versions.
- Update, replace, or remove vulnerable Wire usage where vendor guidance supports it.
- Avoid deserializing Wire payloads from untrusted sources.
- Review forks of Wire for the same vulnerable behavior.
Validation and detection
- Search dependency manifests and lockfiles for the Wire package and version.
- Identify every code path that calls Wire deserialization functions.
- Confirm whether any deserialization input crosses trust boundaries.
- Test that exposed services reject unexpected or untrusted serialized input.
- Document compensating controls if immediate replacement is not possible.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-502: Code execution behavior lookup
Code execution and unsafe deserialization weaknesses often justify reviewing execution behavior and process telemetry. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-29508 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H3.95.2Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
9.1CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/AsynkronIT/Wire/security/advisories/GHSA-hpw7-3vq3-mmv6CVE reference · x_refsource_CONFIRM
- https://www.nuget.org/packages/Wire/CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Deserialization of Untrusted Data
Deserialization of Untrusted Data represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.