dbcve.org
HTTP ServerWeb server / proxy · Apache

CVE-2017-3169

CRITICAL · 9.8 CVSS v3.0 Published 2017-06-20
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
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
In Apache httpd 2.2.x before 2.2.33 and 2.4.x before 2.4.26, mod_ssl may dereference a NULL pointer when third-party modules call ap_hook_process_connection() during an HTTP request to an HTTPS port.

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

A NULL pointer dereference vulnerability exists in mod_ssl in Apache HTTP Server versions 2.2.x before 2.2.33 and 2.4.x before 2.4.26. When third-party modules call ap_hook_process_connection() during an HTTP request to an HTTPS port, mod_ssl may dereference a NULL pointer, potentially leading to a crash or other undefined behavior.

MitigationUpgrade Apache HTTP Server to version 2.2.33 or later for the 2.2.x branch, or version 2.4.26 or later for the 2.4.x branch. Alternatively, ensure no untrusted third-party modules that call ap_hook_process_connection() are loaded.

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
HTTP ServerWeb server / proxy
Affected:= 2.2.0= 2.2.2= 2.2.3= 2.2.11= 2.2.12= 2.2.13= 2.2.14= 2.2.15= 2.2.16= 2.2.17= 2.2.18= 2.2.19

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
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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 Apache version
    Run 'httpd -v' or 'apache2 -v' to retrieve the server version, or query the package manager
    Affected if Version is 2.2.x before 2.2.33 or 2.4.x before 2.4.26
  2. Verify mod_ssl is loaded
    Run 'httpd -M' or 'apache2ctl -M' to list loaded modules, or check configuration files for 'LoadModule ssl_module'
    Affected if mod_ssl is enabled and the server handles HTTPS connections
  3. Identify third-party modules
    Review the module list and configuration for non-standard modules, particularly those that hook into the connection phase via ap_hook_process_connection()
    Affected if Any third-party module that calls ap_hook_process_connection() is loaded
  4. Confirm HTTPS listener exists
    Check server configuration for 'Listen 443' or SSL virtual host definitions
    Affected if The server is configured to accept HTTPS requests on port 443

You are affected if your Apache version is 2.2.x before 2.2.33 or 2.4.x before 2.4.26, mod_ssl is loaded, and a third-party module calling ap_hook_process_connection() is present while the server handles HTTPS traffic.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade Apache HTTP Server to version 2.2.33 or later for the 2.2.x branch, or version 2.4.26 or later for the 2.4.x branch. Alternatively, ensure no untrusted third-party modules that call ap_hook_process_connection() are loaded.

Recommended fix High confidence

Apache httpd 2.4.26 or later (2.4.x recommended; alternatively 2.2.33+ if staying on 2.2.x)

  1. 1. Identify the current Apache httpd version installed using 'httpd -v' or 'apache2 -v'
  2. 2. Download Apache httpd 2.4.x from the official Apache website or your distribution's package repository
  3. 3. Back up your current httpd configuration files (httpd.conf, ssl.conf, and any included files)
  4. 4. Install the new version using your system's package manager (e.g., 'apt-get update && apt-get install apache2' for Debian/Ubuntu, or 'yum install httpd' for RHEL/CentOS)
  5. 5. Review and update configuration files for any deprecated directives or syntax changes between 2.2.x and 2.4.x
  6. 6. Test the configuration with 'apachectl configtest' before restarting
  7. 7. Restart Apache httpd to apply the changes
Caveat Apache 2.2.x reached end-of-life in 2017; upgrading to 2.4.x may require configuration changes for deprecated directives and module API differences

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

Fix this in HTTP Server Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA2.0 h
9.0 hours of engineering $1,570
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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-2017-3169 in production — separate from our analysis above.

No notes yet

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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
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data