In situations where an attacker receives automated notification of the success or failure of a decryption attempt an attacker, after sending a very large number of messages to be decrypted, can recover a CMS/PKCS7 transported encryption key or decrypt any RSA encrypted message that was encrypted with the public RSA key, using a Bleichenbacher padding oracle attack. Applications are not affected if they use a certificate together with the private RSA key to the CMS_decrypt or PKCS7_decrypt functions to select the correct recipient info to decrypt. Fixed in OpenSSL 1.1.1d (Affected 1.1.1-1.1.1c). Fixed in OpenSSL 1.1.0l (Affected 1.1.0-1.1.0k). Fixed in OpenSSL 1.0.2t (Affected 1.0.2-1.0.2s).

References;a=commitdiff;h=08229ad838c50f644d7e928e2eef147b4308ad64;a=commitdiff;h=631f94db0065c78181ca9ba5546ebc8bb3884b97;a=commitdiff;h=e21f8cf78a125cd3c8c0d1a1a6c8bb0b901f893f[email protected]/message/GY6SNRJP2S7Y42GIIDO3HXPNMDYN2U3A/[email protected]/message/ZN4VVQJ3JDCHGIHV4Y2YTXBYQZ6PWQ7E/


Source: MITRE

Published: 2019-09-10

Updated: 2020-10-20

Type: CWE-311

Risk Information

CVSS v2.0

Base Score: 4.3

Vector: AV:N/AC:M/Au:N/C:P/I:N/A:N

Impact Score: 2.9

Exploitability Score: 8.6

Severity: MEDIUM

CVSS v3.0

Base Score: 3.7

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N

Impact Score: 1.4

Exploitability Score: 2.2

Severity: LOW