Vulnerability identifier: #VU17860

Vulnerability risk: Low

CVSSv3.1: 2.7 [CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-1559

CWE-ID: CWE-327

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
OpenSSL
Server applications / Encryption software

Vendor: OpenSSL Software Foundation

Description

The vulnerability allows a remote attacker to decrypt sensitive information.

The vulnerability exists due to the way an application behaves, when it receives a 0-byte record with invalid padding compared to the record with an invalid MAC, which results in padding oracle. A remote attacker can decrypt data.

Successful exploitation of the vulnerability requires that the application is using "non-stitched" ciphersuites and calls SSL_shutdown() twice (first, via a BAD_RECORD_MAC and again via a CLOSE_NOTIFY). 

Mitigation
Install updates from vendor's website.

Vulnerable software versions

OpenSSL: 1.0.2 - 1.0.2q

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External links
http://www.openssl.org/news/secadv/20190226.txt

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.