PyPI: tink
CVE-2020-8929
Safety vulnerability ID: SFTY-20201019-65088
Safety legacy ID: pyup.io-54232
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.
Overview
Ciphertext Malleability Issue in Tink Java
Advisory
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.
How to Fix
Mitigation and Workarounds
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Vulnerable Functions
Functions linked to known vulnerabilities.
References
- https://getsafety.com/vulnerabilities/SFTY-20201019-65088/CVE-2020-8929
- https://github.com/google/tink/security/advisories/GHSA-g5vf-v6wf-7w2r
- https://github.com/google/tink/commit/93d839a5865b9d950dffdc9d0bc99b71280a8899
- https://nvd.nist.gov/vuln/detail/CVE-2020-8929
- https://github.com/pypa/advisory-database/tree/main/vulns/tink/PYSEC-2020-142.yaml
- https://github.com/advisories/GHSA-g5vf-v6wf-7w2r
Verified by Safety
Our Cybersecurity Intelligence Team reviewed this vulnerability. We combine public data with our own research to find issues not yet reported to public sources.
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