CVE-2023-33981Public exploitNetwork attack vector

Message spoofing via noncanonical serialization

Published May 24, 2023 · Updated Jan 16, 2025

Improper integrity validation in Briar before 1.4.22 allows remote authenticated users to spoof other users' messages via crafted duplicates. Briar verifies signed blog, forum, and private-group messages by deserializing and reserializing their bodies without requiring canonical serialization, allowing different wire representations to produce the same signed content and identifiers. A malicious participant must be able to send messages to the relevant group or contact, and the result is message confusion and integrity loss rather than content alteration or service interruption.

CVSS severity6.5
Medium
EPSS probability0.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper integrity validation in Briar before 1.4.22 allows remote authenticated users to spoof other users' messages via crafted duplicates. Briar verifies signed blog, forum, and private-group messages by deserializing and reserializing their bodies without requiring canonical serialization, allowing different wire representations to produce the same signed content and identifiers. A malicious participant must be able to send messages to the relevant group or contact, and the result is message confusion and integrity loss rather than content alteration or service interruption.

The record

CVE
CVE-2023-33981
Published
May 24, 2023
Updated
Jan 16, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-354, T1565.002
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 24, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 16, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.5NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
6.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-354Improper Validation of Integrity Check Value
T1565.002Transmitted Data Manipulation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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