SB2016030202 - Fedora 23 update for openssl

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Main Vulnerability Database SB2016030202

SB2016030202 - Fedora 23 update for openssl

Published: March 2, 2016 Updated: April 24, 2025

Security Bulletin ID SB2016030202
CSH Severity
High
Patch available
YES
Number of vulnerabilities 4
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

High 25% Medium 25% Low 50%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 4 vulnerabilities.


1) Buffer overflow (CVE-ID: CVE-2016-0799)

CWE-ID: CWE-119 - Memory corruption

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


The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to fmtstr function in crypto/bio/b_print.c in OpenSSL improperly calculates string lengths. A remote attacker can cause a denial of service (overflow and out-of-bounds read) or possibly have unspecified other impact via a long string.


2) Double free error (CVE-ID: CVE-2016-0705)

CWE-ID: CWE-415 - Double Free

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


The vulnerability allows a remote unauthenticated attacker to cause DoS condition on the target system.

The weakness exists due to double-free error when parsing DSA private keys. A remote attacker can trigger memory corruption and cause the service to crash.

3) Information disclosure (CVE-ID: CVE-2016-0702)

CWE-ID: CWE-200 - Exposure of sensitive information to an unauthorized actor

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


The vulnerability allows a local attacker to decrypt data passed via encrypted SSL connection.

The vulnerability exists in the MOD_EXP_CTIME_COPY_FROM_PREBUF() function in crypto/bn/bn_exp.c. The application does not properly consider cache-bank access times during modular exponentiation, which makes it easier for local users to discover RSA keys by running a crafted application on the same Intel Sandy Bridge CPU core as a victim and leveraging cache-bank conflicts.

The vulnerability was dubbed "CacheBleed".

4) Information disclosure (CVE-ID: CVE-2016-0800)

CWE-ID: CWE-327 - Use of a Broken or Risky Cryptographic Algorithm

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


The vulnerability allows a remote attacker to decrypt sensitive information.

The vulnerability exists due to usage of weak SSLv2 protocol, which requires to send a ServerVerify message before establishing that a client possesses certain plaintext RSA data. A remote attacker can decrypt TLS ciphertext data by leveraging a Bleichenbacher RSA padding oracle.

The vulnerability is dubbed "DROWN" attack.

Remediation

Install update from vendor's website.

References