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Security Bulletin: Multiple vulnerabilities impact AIX/VIOS due to ISC BIND (CVE-2025-40778, CVE-2025-40780, CVE-2025-8677)

Security Bulletin


Summary

Vulnerabilities in ISC BIND could allow an attacker to inject forged data into the cache (CVE-2025-40778), predict the source port and query ID that BIND will use (CVE-2025-40780), or cause CPU exhaustion (CVE-2025-8677). AIX uses ISC BIND as as part of its DNS functions.

Vulnerability Details

CVEID:   CVE-2025-40778
DESCRIPTION:   Under certain circumstances, BIND is too lenient when accepting records from answers, allowing an attacker to inject forged data into the cache. This issue affects BIND 9 versions 9.11.0 through 9.16.50, 9.18.0 through 9.18.39, 9.20.0 through 9.20.13, 9.21.0 through 9.21.12, 9.11.3-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.39-S1, and 9.20.9-S1 through 9.20.13-S1.
CWE:   CWE-349: Acceptance of Extraneous Untrusted Data With Trusted Data
CVSS Source:   security-officer@isc.org
CVSS Base score:   8.6
CVSS Vector:   (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N)

CVEID:   CVE-2025-40780
DESCRIPTION:   In specific circumstances, due to a weakness in the Pseudo Random Number Generator (PRNG) that is used, it is possible for an attacker to predict the source port and query ID that BIND will use. This issue affects BIND 9 versions 9.16.0 through 9.16.50, 9.18.0 through 9.18.39, 9.20.0 through 9.20.13, 9.21.0 through 9.21.12, 9.16.8-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.39-S1, and 9.20.9-S1 through 9.20.13-S1.
CWE:   CWE-341: Predictable from Observable State
CVSS Source:   security-officer@isc.org
CVSS Base score:   8.6
CVSS Vector:   (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N)

CVEID:   CVE-2025-8677
DESCRIPTION:   Querying for records within a specially crafted zone containing certain malformed DNSKEY records can lead to CPU exhaustion. This issue affects BIND 9 versions 9.18.0 through 9.18.39, 9.20.0 through 9.20.13, 9.21.0 through 9.21.12, 9.18.11-S1 through 9.18.39-S1, and 9.20.9-S1 through 9.20.13-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
VIOS4.1

 

The vulnerabilities are being addressed in the following filesets:

 

FilesetLower LevelUpper Level
bind.rte7.1.916.07.1.916.4800
bind.rte7.2.916.07.2.916.4801
bind.rte7.2.918.07.2.918.2802
bind.rte7.3.916.07.3.916.4800
bind.rte7.3.918.07.3.918.2802

 

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_fix29.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_fix29.tar

 

For AIX 7.2 (requires OpenSSL 3.x):

tar xvf bind_fix29/72bind918.tar

 

For AIX 7.3 and VIOS 4.1:

tar xvf bind_fix29/73bind918.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
789d3ee5df0e7a223c35ef0b27c1e6fc1bdcac01606039a6bcf74182abb1424472bind.rte
6f81f94ca66347929783bb6b6ab6ba8ae2e0e22288e6ecd8a5d887d02f0110ee73bind.rte

 

openssl dgst -sha512filename
12202afcf9f26d286c9421ecbc92160d6ce1b4adcab824175d15633b3982f1375ef0caef5646462046cef020ef8fd944af6cfd4442e52e6d4fc6a0c2b8910d0072bind.rte
db13307fc9efadc97e4b5e6609713bc9082a24395d2177bf67bb596678611379e66631d07ee8ababcad4afa8807a88ef2a65b66207d2e4271a60d1cf222ac22073bind.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_advisory29.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

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References

Complete CVSS v3 Guide
On-line Calculator v3

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Related Information

IBM Secure Engineering Web Portal
IBM Product Security Incident Response Blog

Acknowledgement

Change History

18 Feb 2026: 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:
18 February 2026

Initial Publish date:
18 February 2026

UID

ibm17261171

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