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Traffic ServerApplication · Apache

CVE-2015-3249

CRITICAL · 9.8 CVSS v3.0 Published 2017-10-30
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
The HTTP/2 experimental feature in Apache Traffic Server 5.3.x before 5.3.1 allows remote attackers to cause a denial of service (out-of-bounds access and daemon crash) or possibly execute arbitrary code via vectors related to the (1) frame_handlers array or (2) set_dynamic_table_size function.

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

Apache Traffic Server 5.3.x before 5.3.1 contains an out-of-bounds access vulnerability in its experimental HTTP/2 implementation. The flaw exists in the frame_handlers array handling and the set_dynamic_table_size function used for HTTP/2 HPACK dynamic table operations. Attackers can trigger daemon crashes leading to denial of service, or potentially achieve arbitrary code execution via specially crafted HTTP/2 frames.

MitigationUpgrade Apache Traffic Server to version 5.3.1 or later. If upgrading immediately is not feasible, disable the experimental HTTP/2 feature until the patch can be applied.

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
Traffic ServerApplication
Affected:= 5.3.0

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. Identify Apache Traffic Server version
    Run 'traffic_server -V' or check the package manager (rpm -q ats, dpkg -l ats) to determine the installed version
    Affected if The installed version is 5.3.0 or any 5.3.x version prior to 5.3.1
  2. Confirm HTTP/2 protocol support is enabled
    Inspect the Traffic Server records.config file (commonly in /etc/trafficserver/) for the setting 'proxy.config.http2.enabled'
    Affected if The HTTP/2 protocol support is explicitly enabled (value set to 1 or true) in the configuration
  3. Verify the experimental HTTP/2 module is loaded
    Check if HTTP/2 is listed among enabled protocols in records.config under 'proxy.config.http2.enabled' or in the ssl_multicert.config if using HTTPS
    Affected if HTTP/2 is actively enabled and the server is configured to accept HTTP/2 connections

You are affected if Apache Traffic Server version 5.3.0 is installed AND the experimental HTTP/2 feature is enabled in the configuration, allowing specially crafted HTTP/2 frames to trigger the out-of-bounds access in the HPACK dynamic table handling.

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 Traffic Server to version 5.3.1 or later. If upgrading immediately is not feasible, disable the experimental HTTP/2 feature until the patch can be applied.

Recommended fix Moderate confidence

5.3.1

  1. 1. Back up your current Apache Traffic Server configuration directory (typically /etc/trafficserver or /usr/local/etc/trafficserver)
  2. 2. Back up your Traffic Server data directory
  3. 3. Stop the Traffic Server service using: systemctl stop trafficserver or service trafficserver stop
  4. 4. Download Apache Traffic Server 5.3.1 from the official Apache download site (https://trafficserver.apache.org/downloads)
  5. 5. Install the 5.3.1 package using your system's package manager (yum, apt, rpm, or compile from source)
  6. 6. Restore your configuration backup to ensure settings are preserved
  7. 7. Start the Traffic Server service using: systemctl start trafficserver or service trafficserver start
  8. 8. Verify the server is running and HTTP/2 functionality is operational
Caveat HTTP/2 was experimental in 5.3.0; upgrading to 5.3.1 includes security fixes but may include changes to HTTP/2 handling

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

Fix this in Traffic Server Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
13.0 hours of engineering $2,280
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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-2015-3249 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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