OpenSSL CVE-2014-0160 Heartbleed bug and Red Hat Enterprise Linux

Issue

• Does CVE-2014-0160 affect Red Hat Enterprise Linux?
• Need fix for openssl heartbleed bug
• What versions of Red Hat Enterprise Linux are affected by openssl heartbleed vulnerability?
• Do we have a list of packages/services we ship with RHEL that need a restart after OpenSSL has been updated?

Environment

• Red Hat Enterprise Linux 7 Release Candidate (RC) not affected
• Red Hat Enterprise Linux 7 Beta affected
• Red Hat Enterprise Linux 6 affected
• Red Hat Enterprise Linux 5 not affected
• Red Hat Enterprise Linux 4 not affected
• For other affected products, refer to https://access.redhat.com/site/announcements/781953

Resolution

Step 1: Determine if RHEL system is vulnerable to flaw described in CVE-2014-0160

• Red Hat Enterprise Linux 7 Release Candidate (RC)
  
  • Red Hat Enterprise Linux 7 RC include OpenSSL version openssl-1.0.1e-34.el7 which includes a fix backported from openssl-1.0.1g
• Red Hat Enterprise Linux 7 Beta
  
  • OpenSSL versions openssl-1.0.1e-33.el7 and earlier include a flawed libssl.so library vulnerable to the issue
  • To determine openssl version, use the command: rpm -q openssl
  • Version openssl-1.0.1e-34.el7 included a fix backported from openssl-1.0.1g
  • See footnote for considerations specific to RHEL 7 Beta¹
• Red Hat Enterprise Linux 6
  
  • OpenSSL versions openssl-1.0.1e-15 through openssl-1.0.1e-16.el6_5.4 include a flawed libssl.so library vulnerable to the issue
  • The first affected version shipped with RHEL 6.5 (RHEL 6.4 and older shipped with the unaffected openssl-1.0.0 series)
    • Systems which report as RHEL 6.0 - 6.3 could still have been updated to a newer [vulnerable] openssl-1.0.1 series package
  • To determine openssl version, use the command: rpm -q openssl
  • Version openssl-1.0.1e-16.el6_5.7 included a fix backported from openssl-1.0.1g
• Red Hat Enterprise Linux 5 and Red Hat Enterprise Linux 4
  
  • Vulnerable OpenSSL 1.0.1 series versions never shipped in RHEL 5 or earlier

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Optional Step 2: Look for and/or query processes which are using the vulnerable libssl library

• Run either of the following commands as root to display running processes which are using libssl
  
  • lsof | awk 'NR==1 || $0~/libssl.so.1.0.1e/'
    
  • grep libssl.so.1.0.1e /proc/*/maps | cut -d/ -f3 | sort -u | xargs -r -- ps uf
    
• Use Red Hat's Heartbleed Detector tool to query public-facing servers (or the version for internal systems)
  
• Problem: Both of the above commands find no processes, but one of the Heartbleed detector tools reports system vulnerable!
  

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Step 3: Upgrade the openssl package

• Red Hat Enterprise Linux 7 Beta
  
  • Update to openssl-1.0.1e-34.el7 (which corrected the flaw) or later
• Red Hat Enterprise Linux 6
  
  • Update to openssl-1.0.1e-16.el6_5.7 (which corrected the flaw, as described in RHSA-2014:0376) or later
• As always, registered systems with internet access (or any RHEL 7 Beta system, or systems connected to Satellites, etc) can be updated via yum, e.g.:
  
  • yum update openssl
• Otherwise, use a connected system to download the package or download the package directly from the Customer Portal²
  
  • After that, transfer the package to the system in question and install it manually with yum, e.g.:
    
    • yum update <path-to-openssl*rpm>

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Step 4: After updating openssl, restart all processes using the flawed libssl.so³

• The safest & simplest thing to do: perform a system reboot
  
• Alternatively: use the commands from Optional Step 2 to determine which processes need to be restarted and then act accordingly
  

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Optional Step 5: Re-scan updated systems with one of the Heartbleed Detector tools

• Use the scanners mentioned above in Optional Step 2
• Problem: I updated openssl but the Heartbleed detector tools still report vulnerable!

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Optional Step 6: Take additional remediation steps as desired

• Official statement from Red Hat Security Response Team:
  

  Red Hat is not aware of any public exploit being used in the wild for this issue prior to the date of disclosure. However, a number of public exploits were published shortly after the issue was disclosed.⁴ These exploits could lead to the disclosure of information handled by applications using OpenSSL, including private keys, session tokens, and data submitted by users, which could include authentication credentials. It is recommended that you assess the risk this could pose to your systems, and perform additional remediation as you deem appropriate.
  

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Root Cause

• Official statement from Security Advisory RHSA-2014:0376:
  

  An information disclosure flaw was found in the way OpenSSL handled TLS and
  DTLS Heartbeat Extension packets. A malicious TLS or DTLS client or server
  could send a specially crafted TLS or DTLS Heartbeat packet to disclose a
  limited portion of memory per request from a connected client or server.
  Note that the disclosed portions of memory could potentially include
  sensitive information such as private keys. (CVE-2014-0160)
  

• For links to more detail, see the entry for CVE-2014-0160 in Red Hat's CVE Database