dbcve.org
HTTP ServerWeb server / proxy · Apache

CVE-2018-1312

CRITICAL · 9.8 CVSS v3.1 Published 2018-03-26
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 2.2.0 to 2.4.29, when generating an HTTP Digest authentication challenge, the nonce sent to prevent reply attacks was not correctly generated using a pseudo-random seed. In a cluster of servers using a common Digest authentication configuration, HTTP requests could be replayed across servers by an attacker without detection.

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 Apache httpd 2.2.0 to 2.4.29, the nonce generation for HTTP Digest authentication challenges was not correctly seeded with pseudo-random values. This allowed predictable nonces that could be replayed across servers in a cluster using shared Digest authentication configuration, enabling attackers to replay authenticated HTTP requests without detection.

MitigationUpgrade Apache httpd to version 2.4.30 or later. In clustered environments using Digest authentication, verify the fix is applied consistently across all nodes.

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:= 2.4.1= 2.4.2= 2.4.3= 2.4.4= 2.4.6= 2.4.7= 2.4.9= 2.4.10= 2.4.12= 2.4.16= 2.4.17= 2.4.18
Ubuntu LinuxOperating system
Affected:= 12.04= 14.04= 16.04= 17.10= 18.04
Debian LinuxOperating system
Affected:= 7.0= 8.0= 9.0
Jboss Core ServicesApplication
Affected:= 1.0
Enterprise Linux DesktopOperating system
Affected:= 7.0
Enterprise Linux EusOperating system
Affected:= 7.6
Enterprise Linux ServerOperating system
Affected:= 7.0
Enterprise Linux Server AusOperating system
Affected:= 7.6

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:3.1/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. Identify Apache httpd installation and version
    Run 'httpd -v' or 'apache2 -v' to get the installed version number
    Affected if The version is 2.2.0 through 2.4.29 (or matches the specific versions listed: 2.4.1, 2.4.2, 2.4.3, 2.4.4, 2.4.6, 2.4.7, 2.4.9, 2.4.10, 2.4.12, 2.4.16, 2.4.17, 2.4.18)
  2. Verify HTTP Digest authentication is in use
    Search configuration files (*.conf) for 'AuthType Digest' directive. Check for 'Digest' auth in httpd.conf, ssl.conf, or virtual host configurations
    Affected if AuthType Digest is present in any Apache configuration file
  3. Check for shared or clustered Digest authentication setup
    Inspect whether multiple Apache instances share the same Digest auth configuration or use a common secret/key file. Look for 'AuthDigestDomain' directives and check if this configuration is replicated across servers
    Affected if Digest authentication is used in a clustered environment where configuration is shared across multiple servers

You are affected if Apache httpd version is between 2.2.0 and 2.4.29 AND HTTP Digest authentication is configured, especially in a clustered environment where the predictable nonce could be replayed across servers.

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 httpd to version 2.4.30 or later. In clustered environments using Digest authentication, verify the fix is applied consistently across all nodes.

Recommended fix High confidence

Apache HTTP Server 2.4.30 or later

  1. Identify the current Apache HTTP Server version using 'httpd -v' or 'apache2 -v'
  2. Download Apache HTTP Server 2.4.30 or later from https://httpd.apache.org/
  3. For package-based systems: update via package manager (apt-get update && apt-get install apache2 on Debian/Ubuntu, or yum update httpd on RHEL/CentOS)
  4. Verify the upgrade was successful by checking the version with 'httpd -v'
  5. If using Digest authentication in a clustered environment, ensure all nodes in the cluster are upgraded to the same fixed version
  6. Restart the Apache service to load the new version (systemctl restart httpd or systemctl restart apache2)
  7. Test the Digest authentication mechanism to confirm it is functioning correctly
Caveat This is a security patch release; minimal breaking changes expected. However, test in staging before production deployment.

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

Fix this in HTTP Server Scoped from the published advisory
  • Consultation3.0 h
  • Implementation5.0 h
  • Testing2.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,160
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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-2018-1312 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