Blob plaintext disclosure via CBC padding oracle
Published Jul 12, 2022 · Updated Jul 8, 2025
Padding oracle in Microsoft Azure Storage SDK client-side encryption v1 allows attackers to recover blob plaintext through decryption errors. The v1 implementation decrypts CBC ciphertext with PKCS#5 padding and reveals whether padding validation failed, creating an oracle. Exploitation requires blob write access and repeated observation of an endpoint's decryption failures, yielding plaintext without reported integrity or availability impact.
Summary
What happened
Padding oracle in Microsoft Azure Storage SDK client-side encryption v1 allows attackers to recover blob plaintext through decryption errors. The v1 implementation decrypts CBC ciphertext with PKCS#5 padding and reveals whether padding validation failed, creating an oracle. Exploitation requires blob write access and repeated observation of an endpoint's decryption failures, yielding plaintext without reported integrity or availability impact.
The record
- CVE
- CVE-2022-30187
- Published
- Jul 12, 2022
- Updated
- Jul 8, 2025
- Vendor
- Microsoft
- Product
- Azure Storage Queues client library for .NET
- Classifications
- CWE-327
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 12, 2022CVE publishedPublication date reported by the CVE source.
- Jul 8, 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?
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- Affected versionversion=12.0.0 <12.13.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
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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