dbcve.org
Mac Os XOperating system · Apple

CVE-2015-5887

HIGH · 10.0 CVSS v2.0 Published 2015-10-09
Fix available
A fix is available. Upgrade to after 10.10.5 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
The TLS Handshake Protocol implementation in Secure Transport in Apple OS X before 10.11 accepts a Certificate Request message within a session in which no Server Key Exchange message has been sent, which allows remote attackers to have an unspecified impact via crafted TLS data.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

In Apple's Secure Transport TLS implementation in OS X before 10.11, the handshake state machine incorrectly accepts a Certificate Request message even when no Server Key Exchange message was sent, violating TLS protocol specification. This allows remote attackers to send crafted TLS handshake messages to cause unspecified impact, likely including man-in-the-middle attacks or certificate validation bypass.

MitigationApply OS X 10.11 or later security updates to address the Secure Transport vulnerability. Until patched, monitor TLS traffic for anomalous handshake sequences.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Mac Os XOperating system
Affected:<= 10.10.5

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Authentication
None
Confidentiality
Complete
Integrity
Complete
Availability
Complete

AV:N/AC:L/Au:N/C:C/I:C/A:C

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check installed OS X version
    Run 'sw_vers -productVersion' in Terminal or go to Apple menu > About This Mac
    Affected if Version is 10.10.5 or earlier (10.10.x versions)
  2. Verify Secure Transport is the active TLS backend
    Check if third-party TLS libraries (like OpenSSL) are in use; Secure Transport is default on OS X. Run 'ls /usr/lib/libssl* /usr/lib/libcrypto*' to see if non-Apple TLS libs are loaded
    Affected if Secure Transport is in use (default) and OS X version is 10.10.5 or earlier
  3. Review TLS server configuration for client certificate authentication
    Inspect server config files for SSLVerifyClient or client certificate request settings. Check /etc/httpd/httpd.conf for Apache or relevant server configs
    Affected if Server is configured to request client certificates (Certificate Request) and uses Secure Transport on vulnerable OS X version

A system is affected if it runs OS X 10.10.5 or earlier and uses Apple's Secure Transport for TLS connections, particularly when client certificate authentication is involved.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to a release after 10.10.5
Interim mitigation

Apply OS X 10.11 or later security updates to address the Secure Transport vulnerability. Until patched, monitor TLS traffic for anomalous handshake sequences.

Recommended fix Moderate confidence

Mac OS X 10.11 (El Capitan) or later

  1. Back up all important data on the affected Mac to an external drive or Time Machine backup
  2. Ensure the Mac meets the system requirements for macOS El Capitan (10.11) or later
  3. Download macOS El Capitan (10.11) or a later supported macOS version from the Mac App Store or Apple's website
  4. Run the installer to upgrade the operating system to version 10.11 or later
  5. After upgrade, verify the Secure Transport implementation has been updated by checking System Preferences > About for the OS version
  6. Restart the system and verify TLS functionality works correctly with updated applications
Caveat Upgrading to El Capitan may cause compatibility issues with older 32-bit applications; some legacy software may no longer function

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Mac Os X Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing4.0 h
  • Review / QA2.0 h
9.0 hours of engineering $1,540
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2015-5887 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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