dbcve.org
HTTP ServerWeb server / proxy · Apache

CVE-2018-1283

MEDIUM · 5.3 CVSS v3.0 Published 2018-03-26
Fix available
A fix is available. Upgrade to after 2.4.29 or later.
See remediation →
59/100
Remediation priority · Elevated
Remotely reachable 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 2.4.0 to 2.4.29, when mod_session is configured to forward its session data to CGI applications (SessionEnv on, not the default), a remote user may influence their content by using a "Session" header. This comes from the "HTTP_SESSION" variable name used by mod_session to forward its data to CGIs, since the prefix "HTTP_" is also used by the Apache HTTP Server to pass HTTP header fields, per CGI specifications.

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 2.4.0-2.4.29, when mod_session is configured with SessionEnv on to forward session data to CGI applications, a remote attacker can send a 'Session' HTTP header. This header gets mapped to the HTTP_SESSION CGI environment variable due to Apache's CGI specification behavior, potentially allowing the attacker to influence or spoof the session data that CGI applications receive.

MitigationUpgrade to Apache httpd 2.4.30 or later, or disable SessionEnv if not required by the application.

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:>= 2.4.0, <= 2.4.29
Debian LinuxOperating system
Affected:= 8.0= 9.0
Ubuntu LinuxOperating system
Affected:= 14.04= 16.04= 17.10= 18.04
Enterprise LinuxOperating system
Affected:= 6.0= 7.0= 7.4= 7.5= 7.6
Santricity Cloud ConnectorApplication
Affected:all versions
Storage Automation StoreApplication
Affected:all versions
StoragegridApplication
Affected:all versions
Clustered Data OntapOperating system
Affected:all versions

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

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

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 installed Apache httpd version
    Run 'httpd -v' or 'apache2 -v' to get the server version
    Affected if Version is 2.4.0 through 2.4.29 inclusive
  2. Verify mod_session module is loaded
    Check if 'mod_session' or 'mod_session.so' appears in the loaded modules list via 'httpd -M' or 'apache2ctl -M'
    Affected if mod_session module is loaded and active
  3. Confirm SessionEnv directive is enabled
    Search configuration files (httpd.conf, apache2.conf, included config files) for 'SessionEnv On' directive
    Affected if SessionEnv is explicitly set to On in the configuration

A system is affected only if it runs Apache httpd 2.4.0-2.4.29, has mod_session loaded, and has SessionEnv set to On, allowing an attacker to inject session data via the Session HTTP header.

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.

From vendor data
Upgrade available Upgrade to a release after 2.4.29
Interim mitigation

Upgrade to Apache httpd 2.4.30 or later, or disable SessionEnv if not required by the application.

Fix this in HTTP Server Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing1.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,090
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,744.

Scan for this in your stack

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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-2018-1283 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