IBM Support

PK91361: CVE-2009-1891: MOD_DEFLATE

Fixes are available

IBM HTTP Server interim fix for PK91361
7.0.0.7: WebSphere Application Server V7.0 Fix Pack 7 for IBM i
7.0.0.7: WebSphere Application Server V7.0 Fix Pack 7 for AIX
7.0.0.7: WebSphere Application Server V7.0 Fix Pack 7 for Windows
7.0.0.7: WebSphere Application Server V7.0 Fix Pack 7 for HP-UX
7.0.0.7: Java SDK 1.6 SR6 Cumulative Fix for WebSphere Application Server
7.0.0.7: WebSphere Application Server V7.0 Fix Pack 7 for Solaris
7.0.0.7: WebSphere Application Server V7.0 Fix Pack 7 for Linux
7.0.0.9: WebSphere Application Server V7.0 Fix Pack 9 for IBM i
7.0.0.9: WebSphere Application Server V7.0 Fix Pack 9 for Windows
7.0.0.9: WebSphere Application Server V7.0 Fix Pack 9 for AIX
7.0.0.9: WebSphere Application Server V7.0 Fix Pack 9 for HP-UX
7.0.0.9: Java SDK 1.6 SR7 Cumulative Fix for WebSphere Application Server
7.0.0.9: WebSphere Application Server V7.0 Fix Pack 9 for Solaris
7.0.0.9: WebSphere Application Server V7.0 Fix Pack 9 for Linux
7.0.0.11: WebSphere Application Server V7.0 Fix Pack 11 for IBM i
7.0.0.11: WebSphere Application Server V7.0 Fix Pack 11 for Windows
7.0.0.11: WebSphere Application Server V7.0 Fix Pack 11 for HP-UX
7.0.0.11: WebSphere Application Server V7.0 Fix Pack 11 for AIX
7.0.0.11: Java SDK 1.6 SR7 Cumulative Fix for WebSphere Application Server
7.0.0.11: WebSphere Application Server V7.0 Fix Pack 11 for Solaris
7.0.0.11: WebSphere Application Server V7.0 Fix Pack 11 for Linux
6.1.0.29: Java SDK 1.5 SR11 Cumulative Fix for WebSphere Application Server
6.1.0.31: Java SDK 1.5 SR11 Cumulative Fix for WebSphere Application Server
6.1.0.33: Java SDK 1.5 SR12 FP1 Cumulative Fix for WebSphere
7.0.0.13: WebSphere Application Server V7.0 Fix Pack 13 for AIX
7.0.0.13: WebSphere Application Server V7.0 Fix Pack 13 for HP-UX
7.0.0.13: WebSphere Application Server V7.0 Fix Pack 13 for IBM i
7.0.0.13: WebSphere Application Server V7.0 Fix Pack 13 for Linux
7.0.0.13: WebSphere Application Server V7.0 Fix Pack 13 for Solaris
7.0.0.13: WebSphere Application Server V7.0 Fix Pack 13 for Windows
7.0.0.13: Java SDK 1.6 SR8FP1 Cumulative Fix for WebSphere Application Server
6.1.0.35: Java SDK 1.5 SR12 FP2 Cumulative Fix for WebSphere
7.0.0.15: WebSphere Application Server V7.0 Fix Pack 15 for AIX
7.0.0.15: Java SDK 1.6 SR9 Cumulative Fix for WebSphere Application Server
7.0.0.15: WebSphere Application Server V7.0 Fix Pack 15 for HP-UX
7.0.0.15: WebSphere Application Server V7.0 Fix Pack 15 for IBM i
7.0.0.15: WebSphere Application Server V7.0 Fix Pack 15 for Linux
7.0.0.15: WebSphere Application Server V7.0 Fix Pack 15 for Solaris
7.0.0.15: WebSphere Application Server V7.0 Fix Pack 15 for Windows
6.1.0.37: Java SDK 1.5 SR12 FP3 Cumulative Fix for WebSphere
7.0.0.17: WebSphere Application Server V7.0 Fix Pack 17
7.0.0.17: Java SDK 1.6 SR9 FP1 Cumulative Fix for WebSphere Application Server
7.0.0.19: WebSphere Application Server V7.0 Fix Pack 19
7.0.0.21: WebSphere Application Server V7.0 Fix Pack 21
7.0.0.23: WebSphere Application Server V7.0 Fix Pack 23
7.0.0.25: WebSphere Application Server V7.0 Fix Pack 25
7.0.0.27: WebSphere Application Server V7.0 Fix Pack 27
7.0.0.29: WebSphere Application Server V7.0 Fix Pack 29
6.1.0.47: WebSphere Application Server V6.1 Fix Pack 47
7.0.0.31: WebSphere Application Server V7.0 Fix Pack 31
7.0.0.27: Java SDK 1.6 SR13 FP2 Cumulative Fix for WebSphere Application Server
7.0.0.33: WebSphere Application Server V7.0 Fix Pack 33
7.0.0.35: WebSphere Application Server V7.0 Fix Pack 35
6.1.0.39: Java SDK 1.5 SR12 FP4 Cumulative Fix for WebSphere Application Server
6.1.0.41: Java SDK 1.5 SR12 FP5 Cumulative Fix for WebSphere Application Server
6.1.0.43: Java SDK 1.5 SR13 Cumulative Fix for WebSphere Application Server
6.1.0.45: Java SDK 1.5 SR14 Cumulative Fix for WebSphere Application Server
6.1.0.47: Java SDK 1.5 SR16 Cumulative Fix for WebSphere Application Server
7.0.0.19: Java SDK 1.6 SR9 FP2 Cumulative Fix for WebSphere Application Server
7.0.0.21: Java SDK 1.6 SR9 FP2 Cumulative Fix for WebSphere
7.0.0.23: Java SDK 1.6 SR10 FP1 Cumulative Fix for WebSphere
7.0.0.25: Java SDK 1.6 SR11 Cumulative Fix for WebSphere Application Server
7.0.0.27: Java SDK 1.6 SR12 Cumulative Fix for WebSphere Application Server
7.0.0.29: Java SDK 1.6 SR13 FP2 Cumulative Fix for WebSphere Application Server
7.0.0.45: Java SDK 1.6 SR16 FP60 Cumulative Fix for WebSphere Application Server
7.0.0.31: Java SDK 1.6 SR15 Cumulative Fix for WebSphere Application Server
7.0.0.35: Java SDK 1.6 SR16 FP1 Cumulative Fix for WebSphere Application Server
7.0.0.37: Java SDK 1.6 SR16 FP3 Cumulative Fix for WebSphere Application Server
7.0.0.39: Java SDK 1.6 SR16 FP7 Cumulative Fix for WebSphere Application Server
7.0.0.41: Java SDK 1.6 SR16 FP20 Cumulative Fix for WebSphere Application Server
7.0.0.43: Java SDK 1.6 SR16 FP41 Cumulative Fix for WebSphere Application Server

Subscribe

You can track all active APARs for this component.

APAR status

  • Closed as program error.

Error description

  • IHS compression module mod_deflate continues compressing
    response after client hangup.  This potentially exposes the
    server to a Denial-of-Service attack by forcing the server to
    consume CPU time in compressing a large response after a client
    disconnects.  Out of the box, IHS does not use mod_deflate, but
    if you plug in a module that uses mod_deflate, you are
    potentially at risk.
    

Local fix

  • Disable the optional mod_deflate module, or disable deflate of
    potentially large content.
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED: IHS 6.x, 7.0 using mod_deflate               *
    ****************************************************************
    * PROBLEM DESCRIPTION: Attacker can force extra CPU usage by   *
    * requesting large responses then disconnecting, causing       *
    * IHS to still compress the response.                          *
    ****************************************************************
    * RECOMMENDATION: Apply this fix if mod_deflate is enabled.    *
    ****************************************************************
    CVE-2009-1891 potential Denial-of-Service attack against
    mod_deflate or other modules, by forcing the server to consume
    CPU time in compressing a large response after a client
    disconnects.
    

Problem conclusion

  • Fix ported from Apache to detect client disconnect and abort
    the compression.
    
    This fix is targeted for IHS fixpacks:
     - 6.0.2.39
     - 6.1.0.29
     - 7.0.0.7
    

Temporary fix

Comments

APAR Information

  • APAR number

    PK91361

  • Reported component name

    IBM HTTP SERVER

  • Reported component ID

    5724J0801

  • Reported release

    61A

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2009-07-14

  • Closed date

    2009-07-21

  • Last modified date

    2009-10-15

  • APAR is sysrouted FROM one or more of the following:

  • APAR is sysrouted TO one or more of the following:

Fix information

  • Fixed component name

    IBM HTTP SERVER

  • Fixed component ID

    5724J0801

Applicable component levels

  • R60A PSN

       UP

  • R60H PSN

       UP

  • R60I PSN

       UP

  • R60P PSN

       UP

  • R60S PSN

       UP

  • R60W PSN

       UP

  • R60Z PSN

       UP

  • R61A PSN

       UP

  • R61H PSN

       UP

  • R61I PSN

       UP

  • R61P PSN

       UP

  • R61S PSN

       UP

  • R61W PSN

       UP

  • R61Z PSN

       UP

  • R700 PSN

       UP



Document information

More support for: IBM HTTP Server
Runtime

Software version: 6.1

Reference #: PK91361

Modified date: 15 October 2009