Encrypted-data disclosure via unmatched public key
Published Aug 18, 2021 · Updated Aug 3, 2024
Improper certificate validation in Nextcloud Desktop Client before 3.3.0 allows attackers to read encrypted data via a malicious public key. During E2EE setup, ClientSideEncryption accepts the server-supplied public certificate without verifying that it matches the downloaded private key. Exploitation requires a malicious or compromised Nextcloud instance; affected clients then encrypt synchronized data for the attacker's key.
Summary
What happened
Improper certificate validation in Nextcloud Desktop Client before 3.3.0 allows attackers to read encrypted data via a malicious public key. During E2EE setup, ClientSideEncryption accepts the server-supplied public certificate without verifying that it matches the downloaded private key. Exploitation requires a malicious or compromised Nextcloud instance; affected clients then encrypt synchronized data for the attacker's key.
The record
- CVE
- CVE-2021-32728
- Published
- Aug 18, 2021
- Updated
- Aug 3, 2024
- Vendor
- Nextcloud GmbH
- Product
- Nextcloud Security Advisories
- Classifications
- CWE-295
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 18, 2021CVE publishedPublication date reported by the CVE source.
- Aug 3, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=< 3.3.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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