CVE - CVE-2020-26263

CVE-ID
CVE-2020-26263	Learn more at National Vulnerability Database (NVD) • CVSS Severity Rating • Fix Information • Vulnerable Software Versions • SCAP Mappings • CPE Information
Description
tlslite-ng is an open source python library that implements SSL and TLS cryptographic protocols. In tlslite-ng before versions 0.7.6 and 0.8.0-alpha39, the code that performs decryption and padding check in RSA PKCS#1 v1.5 decryption is data dependant. In particular, the code has multiple ways in which it leaks information about the decrypted ciphertext. It aborts as soon as the plaintext doesn't start with 0x00, 0x02. All TLS servers that enable RSA key exchange as well as applications that use the RSA decryption API directly are vulnerable. This is patched in versions 0.7.6 and 0.8.0-alpha39. Note: the patches depend on Python processing the individual bytes in side-channel free manner, this is known to not the case (see reference). As such, users that require side-channel resistance are recommended to use different TLS implementations, as stated in the security policy of tlslite-ng.
References
Note: References are provided for the convenience of the reader to help distinguish between vulnerabilities. The list is not intended to be complete.
CONFIRM:https://github.com/tlsfuzzer/tlslite-ng/security/advisories/GHSA-wvcv-832q-fjg7 URL:https://github.com/tlsfuzzer/tlslite-ng/security/advisories/GHSA-wvcv-832q-fjg7 MISC:https://github.com/tlsfuzzer/tlslite-ng/commit/c28d6d387bba59d8bd5cb3ba15edc42edf54b368 URL:https://github.com/tlsfuzzer/tlslite-ng/commit/c28d6d387bba59d8bd5cb3ba15edc42edf54b368 MISC:https://github.com/tlsfuzzer/tlslite-ng/pull/438 URL:https://github.com/tlsfuzzer/tlslite-ng/pull/438 MISC:https://github.com/tlsfuzzer/tlslite-ng/pull/439 URL:https://github.com/tlsfuzzer/tlslite-ng/pull/439 MISC:https://pypi.org/project/tlslite-ng/ URL:https://pypi.org/project/tlslite-ng/ MISC:https://securitypitfalls.wordpress.com/2018/08/03/constant-time-compare-in-python/ URL:https://securitypitfalls.wordpress.com/2018/08/03/constant-time-compare-in-python/
Assigning CNA
GitHub (maintainer security advisories)
Date Record Created
20201001	Disclaimer: The record creation date may reflect when the CVE ID was allocated or reserved, and does not necessarily indicate when this vulnerability was discovered, shared with the affected vendor, publicly disclosed, or updated in CVE.
Phase (Legacy)
Assigned (20201001)
Votes (Legacy)

Comments (Legacy)

Proposed (Legacy)
N/A
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