Python-rsa is vulnerable to Bleichenbacher timing attacks in the RSA decryption API, via timed processing of valid PKCS#1 v1.5 ciphertext.
Created python-rsa tracking bugs for this issue:
Affects: epel-all [bug 1895780]
Affects: fedora-all [bug 1895779]
Fix doc text: the vulnerability *is* present, it is *not* fixed—there are no patches proposed to fix it.
I haven't looked at the old code, but I don't expect any old versions to be secure, the issue at least partially stems from the fact that the API raises an exception in case of malformed plaintext, so all versions that can raise an exception in decryption API are vulnerable.
It looks like all versions since 2.1 (inclusive) are vulnerable, versions before 2.1 don't provide RSA decryption API: https://github.com/sybrenstuvel/python-rsa/commit/714324a9a34f0958704e5064251a1f00ed37a372
Name: Hubert Kario