CVE-2020-8929

Ciphertext integrity weakness in Tink

MEDIUM
5.3
CVSS Score
Published: October 19, 2020 at 12:15 PM UTC
Updated: June 17, 2026 at 03:27 AM UTC
1 product affected across 1 vendorTink-Java

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Severity
MEDIUM5.3
Exploit prediction
EPSS 0.5%

Description

A mis-handling of invalid unicode characters in the Java implementation of Tink versions prior to 1.5 allows an attacker to change the ID part of a ciphertext, which result in the creation of a second ciphertext that can decrypt to the same plaintext. This can be a problem with encrypting deterministic AEAD with a single key, and rely on a unique ciphertext-per-plaintext.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 1.5.0stable ≤ v < 1.5stable
Affected range stops below 1.5, so it looks safe — our inference, not a vendor statement
Affected range stops below 1.5.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

CVSS

5.3MEDIUMGoogle
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-176NVD-CWE-Other

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