SB2017120804 - Multiple vulnerabilities in OpenSSL



SB2017120804 - Multiple vulnerabilities in OpenSSL

Published: December 8, 2017

Security Bulletin ID SB2017120804
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 2
Exploitation vector Remote access
Highest impact Data manipulation

Breakdown by Severity

Medium 50% Low 50%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 2 vulnerabilities.


1) Improper input validation (CVE-ID: CVE-2017-3737)

CWE-ID: CWE-20 - Improper input validation

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to gain access to potentially sensitive information on the target system.

The weakness exists due to an "error state mechanism" when SSL_read() or SSL_write() is called directly after SSL object. A remote attacker can a specially crafted input, trigger a fatal error during a handshake and return it in the initial function call to access or modify sensitive information.

2) Buffer overflow (CVE-ID: CVE-2017-3738)

CWE-ID: CWE-120 - Buffer overflow

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear


The vulnerability allows a remote attacker to obtain potentially sensitive information on the target system.

The weakness exists due to buffer overflow in the AVX2 Montgomery multiplication procedure used in exponentiation with 1024-bit moduli. A remote attacker can cause the server to share the DH1024 private key among multiple clients and perform attack on TLS.

Remediation

Install update from vendor's website.