IBM SECURITY ADVISORY
First Issued: Tue May 20 08:16:08 CDT 2025
The most recent version of this document is available here:
https://aix.software.ibm.com/aix/efixes/security/bind_advisory28.asc
Security Bulletin: AIX is vulnerable to a denial of service due to ISC BIND
===============================================================================
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
https://www.cve.org/CVERecord?id=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.
CVSS Base Score: 7.5
CVSS Environmental Score*: Undefined
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
https://www.cve.org/CVERecord?id=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.
CVSS Base Score: 7.5
CVSS Environmental Score*: Undefined
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:
AIX 7.2, 7.3
VIOS 3.1, 4.1
The following fileset levels are vulnerable:
key_fileset = aix
Fileset Lower Level Upper Level KEY
----------------------------------------------------------
bind.rte 7.1.916.0 7.1.916.4800 key_w_fs
bind.rte 7.2.916.0 7.2.916.4801 key_w_fs
bind.rte 7.2.918.0 7.2.918.2800 key_w_fs
bind.rte 7.3.916.0 7.3.916.4800 key_w_fs
bind.rte 7.3.918.0 7.3.918.2800 key_w_fs
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:
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 -sha256 filename KEY
---------------------------------------------------------------------------------------
433ca0d5edb9af9c063aa85ce534131911e5a59a3acb01230a413037936d2966 72bind.rte key_w_csum
a926b51554425b2480fc733855aac979215846cb5adbdd92bdd766355f40f4db 73bind.rte key_w_csum
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.
===============================================================================
CONTACT US:
Note: Keywords labeled as KEY in this document are used for parsing
purposes.
If you would like to receive AIX Security Advisories via email,
please visit "My Notifications":
https://www.ibm.com/support/mynotifications
Contact IBM Support for questions related to this announcement:
https://ibm.com/support/
For information on how to securely verify AIX security bulletins and fixes:
https://www.ibm.com/support/pages/node/6985269
To obtain the OpenSSL public key that can be used to verify the
signed advisories and ifixes:
Download the key from our web page:
https://aix.software.ibm.com/aix/efixes/security/systems_p_os_aix_security_pubkey.txt
To verify the AIX/VIOS security bulletin:
Published advisory OpenSSL signature file location:
https://aix.software.ibm.com/aix/efixes/security/bind_advisory28.asc.sig
openssl dgst -sha256 -verify [pubkey_file] -signature [advisory_file].sig [advisory_file]
Please contact your local IBM AIX support center for any
assistance.
REFERENCES:
Complete CVSS v3 Guide: http://www.first.org/cvss/user-guide
On-line Calculator v3:
http://www.first.org/cvss/calculator/3.0
RELATED INFORMATION:
IBM Secure Engineering Web Portal
http://www.ibm.com/security/secure-engineering/bulletins.html
IBM Product Security Incident Response Blog
https://www.ibm.com/blogs/psirt/
Security Bulletin: AIX is vulnerable to denial of service due to ISC BIND
https://www.ibm.com/support/pages/node/7233964
ACKNOWLEDGEMENTS:
None.
CHANGE HISTORY:
First Issued: Tue May 20 08:16:08 CDT 2025
===============================================================================
*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.