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Helix ServerApplication · Realnetworks

CVE-2008-5911

HIGH · 10.0 CVSS v2.0 Published 2009-01-20
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
Multiple buffer overflows in RealNetworks Helix Server and Helix Mobile Server 11.x before 11.1.8 and 12.x before 12.0.1 allow remote attackers to (1) cause a denial of service via three crafted RTSP SETUP commands, or execute arbitrary code via (2) an NTLM authentication request with malformed base64-encoded data, (3) an RTSP DESCRIBE command, or (4) a DataConvertBuffer request.

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

RealNetworks Helix Server and Helix Mobile Server contain multiple buffer overflow vulnerabilities in handling RTSP protocol commands. Attackers can trigger the vulnerabilities through crafted RTSP SETUP, DESCRIBE, and NTLM authentication requests, as well as DataConvertBuffer requests. Successful exploitation allows denial of service or arbitrary code execution with the privileges of the affected service.

MitigationUpgrade Helix Server 11.x to version 11.1.8 or later, and 12.x to version 12.0.1 or later. If immediate patching is not possible, consider restricting RTSP access to trusted sources via firewall rules or network segmentation.

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
Helix ServerApplication
Affected:= 11.0= 12.0.0
Helix Server MobileApplication
Affected:= 11.0= 12.0.0

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
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. Identify if Helix Server is installed
    Locate the Helix Server installation directory or check for helix-server process/service on the system
    Affected if Helix Server or Helix Server Mobile software is present
  2. Determine the installed version
    Use the product's version lookup mechanism (such as checking the binary, help menu, or admin interface) to obtain the exact version number
    Affected if The installed version is 11.0 or 12.0.0 specifically
  3. Check if RTSP service is enabled
    Verify whether the RTSP (Real Time Streaming Protocol) service or module is active and listening on the server
    Affected if RTSP service is enabled and accessible (this is the attack vector)
  4. Compare against affected version range
    Cross-reference the detected version against the vulnerable versions (11.0 and 12.0.0)
    Affected if The running version matches exactly 11.0 or 12.0.0

If Helix Server or Helix Server Mobile version 11.0 or 12.0.0 is installed with RTSP protocol handling enabled, the environment is affected by this vulnerability.

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 Helix Server 11.x to version 11.1.8 or later, and 12.x to version 12.0.1 or later. If immediate patching is not possible, consider restricting RTSP access to trusted sources via firewall rules or network segmentation.

Recommended fix High confidence

Helix Server 11.1.8 (for 11.x) or 12.0.1 (for 12.x), or migrate to a later supported release

  1. 1. Identify the currently installed Helix Server or Helix Mobile Server version.
  2. 2. Download Helix Server version 11.1.8 or later (for 11.x installations), or version 12.0.1 or later (for 12.x installations, as 12.0.1 addresses the vulnerabilities).
  3. 3. Review the RealNetworks migration/upgrade documentation for Helix Server before proceeding.
  4. 4. Back up the current server configuration, settings, and media assets.
  5. 5. Stop the Helix Server service.
  6. 6. Install the upgraded version (11.1.8 or later for 11.x; 12.0.1 or later for 12.x).
  7. 7. Restore the backed-up configuration to the new installation.
  8. 8. Restart the Helix Server service.

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

Fix this in Helix Server Scoped from the published advisory
  • Consultation3.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,920
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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-2008-5911 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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