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Security Bulletin: AIX/VIOS is vulnerable to a denial of service due to ISC BIND

Security Bulletin


Summary

Vulnerabilities in ISC BIND could allow a remote attacker to cause a denial of service (CVE-2024-12705, CVE-2024-11187). AIX uses ISC BIND as as part of its DNS functions.

Vulnerability Details

CVEID:   CVE-2024-12705
DESCRIPTION:   Clients using DNS-over-HTTPS (DoH) can exhaust a DNS resolver's CPU and/or memory by flooding it with crafted valid or invalid HTTP/2 traffic. This issue affects BIND 9 versions 9.18.0 through 9.18.32, 9.20.0 through 9.20.4, 9.21.0 through 9.21.3, and 9.18.11-S1 through 9.18.32-S1.
CWE:   CWE-770: Allocation of Resources Without Limits or Throttling
CVSS Source:   security-officer@isc.org
CVSS Base score:   7.5
CVSS Vector:   (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

CVEID:   CVE-2024-11187
DESCRIPTION:   It is possible to construct a zone such that some queries to it will generate responses containing numerous records in the Additional section. An attacker sending many such queries can cause either the authoritative server itself or an independent resolver to use disproportionate resources processing the queries. Zones will usually need to have been deliberately crafted to attack this exposure. This issue affects BIND 9 versions 9.11.0 through 9.11.37, 9.16.0 through 9.16.50, 9.18.0 through 9.18.32, 9.20.0 through 9.20.4, 9.21.0 through 9.21.3, 9.11.3-S1 through 9.11.37-S1, 9.16.8-S1 through 9.16.50-S1, and 9.18.11-S1 through 9.18.32-S1.
CWE:   CWE-405: Asymmetric Resource Consumption (Amplification)
CVSS Source:   security-officer@isc.org
CVSS Base score:   7.5
CVSS Vector:   (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

Affected Products and Versions

Affected Product(s)Version(s)
AIX7.2
AIX7.3
VIOS3.1
VIOS4.1

 

The following fileset levels are vulnerable:

 

FilesetLower LevelUpper Level
bind.rte7.1.916.07.1.916.4800
bind.rte7.2.916.07.2.916.4801
bind.rte7.2.918.07.2.918.2800
bind.rte7.3.916.07.3.916.4800
bind.rte7.3.918.07.3.918.2800

 

Note:

        A. Latest level of BIND fileset is available from the web download site:

        https://www.ibm.com/resources/mrs/assets?source=aixbp

 

To find out whether the affected filesets are installed on your systems, refer to the lslpp command found in AIX user's guide.

 

Example:  lslpp -L | grep -i bind.rte

 

Remediation/Fixes

A. FIXES

 

IBM strongly recommends addressing the vulnerability now.

 

The AIX and VIOS fixes can be downloaded via https from:

https://aix.software.ibm.com/aix/efixes/security/bind_fix28.tar 

 

The fileset update has a dependency on OpenSSL 3.0. OpenSSL 3.0 may be downloaded from:

https://www.ibm.com/resources/mrs/assets?source=aixbp

 

The link above is to a tar file containing this signed advisory, install packages, and OpenSSL signatures for each package. The fixes below include prerequisite checking. This will enforce the correct mapping between the fixes and AIX Technology Levels.

 

To extract the fixes from the tar file:

tar xvf bind_fix28.tar

 

For AIX 7.2 and VIOS 3.1 (requires OpenSSL 3.0):

tar xvf bind_fix28/72bind918.tar

 

For AIX 7.3 and VIOS 4.1:

tar xvf bind_fix28/73bind918.tar

 

IMPORTANT: If possible, it is recommended that a mksysb backup of the system be created. Verify it is both bootable and readable before proceeding.

 

To preview the fix installation:

installp -apYd . bind 

 

To install the fix package:

installp -aXYd . bind

 

Verify you have retrieved the fixes intact:

The checksums below were generated using the "openssl dgst -sha256 [file]" command as the following:

 

openssl dgst -sha256filename
433ca0d5edb9af9c063aa85ce534131911e5a59a3acb01230a413037936d296672bind.rte
a926b51554425b2480fc733855aac979215846cb5adbdd92bdd766355f40f4db73bind.rte

 

These sums should match exactly. The OpenSSL signatures in the tar file and on this advisory can also be used to verify the integrity of the fixes.  If the sums or signatures cannot be confirmed, contact IBM Support at http://ibm.com/support/ and describe the discrepancy.         

 

openssl dgst -sha256 -verify [pubkey_file] -signature [advisory_file].sig [advisory_file]

openssl dgst -sha256 -verify [pubkey_file] -signature [ifix_file].sig [ifix_file]

 

Published advisory OpenSSL signature file location:

https://aix.software.ibm.com/aix/efixes/security/bind_advisory28.asc.sig

 

B. FIX AND INTERIM FIX INSTALLATION

 

If possible, it is recommended that a mksysb backup of the system be created. Verify it is both bootable and readable before proceeding.

 

To preview a fix installation:

installp -a -d fix_name -p all  # where fix_name is the name of the

                                            # fix package being previewed.

 

To install a fix package:

installp -a -d fix_name -X all  # where fix_name is the name of the

                                            # fix package being installed.

 

Interim fixes have had limited functional and regression testing but not the full regression testing that takes place for Service Packs; however, IBM does fully support them.

 

Interim fix management documentation can be found at:

https://www.ibm.com/support/pages/managing-interim-fixes-aix

 

To preview an interim fix installation:

emgr -e ipkg_name -p         # where ipkg_name is the name of the

                                         # interim fix package being previewed.

 

To install an interim fix package:

emgr -e ipkg_name -X         # where ipkg_name is the name of the

                                         # interim fix package being installed.

 

Workarounds and Mitigations

None

Get Notified about Future Security Bulletins

References

Off

Acknowledgement

Change History

20 May 2025: Initial Publication

*The CVSS Environment Score is customer environment specific and will ultimately impact the Overall CVSS Score. Customers can evaluate the impact of this vulnerability in their environments by accessing the links in the Reference section of this Security Bulletin.

Disclaimer

According to the Forum of Incident Response and Security Teams (FIRST), the Common Vulnerability Scoring System (CVSS) is an "industry open standard designed to convey vulnerability severity and help to determine urgency and priority of response." IBM PROVIDES THE CVSS SCORES ""AS IS"" WITHOUT WARRANTY OF ANY KIND, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. CUSTOMERS ARE RESPONSIBLE FOR ASSESSING THE IMPACT OF ANY ACTUAL OR POTENTIAL SECURITY VULNERABILITY. In addition to other efforts to address potential vulnerabilities, IBM periodically updates the record of components contained in our product offerings. As part of that effort, if IBM identifies previously unidentified packages in a product/service inventory, we address relevant vulnerabilities regardless of CVE date. Inclusion of an older CVEID does not demonstrate that the referenced product has been used by IBM since that date, nor that IBM was aware of a vulnerability as of that date. We are making clients aware of relevant vulnerabilities as we become aware of them. "Affected Products and Versions" referenced in IBM Security Bulletins are intended to be only products and versions that are supported by IBM and have not passed their end-of-support or warranty date. Thus, failure to reference unsupported or extended-support products and versions in this Security Bulletin does not constitute a determination by IBM that they are unaffected by the vulnerability. Reference to one or more unsupported versions in this Security Bulletin shall not create an obligation for IBM to provide fixes for any unsupported or extended-support products or versions.

Document Location

Worldwide

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Document Information

Modified date:
20 May 2025

Initial Publish date:
20 May 2025

UID

ibm17233964