CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
AI Score
Confidence
High
EPSS
Percentile
92.9%
IBM SECURITY ADVISORY
First Issued: Tue Jun 4 16:06:25 CDT 2024
|Updated: Wed Jun 5 08:17:08 CDT 2024
|Update: Corrected the affected fileset levels to reflect that
| bind.rte 7.1.916.2604 and 7.3.916.2601 are vulnerable.
The most recent version of this document is available here:
https://aix.software.ibm.com/aix/efixes/security/bind_advisory26.asc
Security Bulletin: AIX is vulnerable to denial of service due to ISC BIND
===============================================================================
SUMMARY:
Multiple vulnerabilities in ISC BIND could allow a remote attacker to
cause a denial of service. AIX uses ISC BIND as part of its DNS functions.
===============================================================================
VULNERABILITY DETAILS:
CVEID: CVE-2023-50868
https://vulners.com/cve/CVE-2023-50868
DESCRIPTION: ISC BIND is vulnerable to a denial of service, caused by an
error when preparing an NSEC3 closest encloser proof. By flooding the
target resolver with queries, a remote attacker could exploit this
vulnerability to cause CPU exhaustion on a DNSSEC-validating resolver.
CVSS Base Score: 7.5
CVSS Temporal Score: See
https://exchange.xforce.ibmcloud.com/vulnerabilities/282901
for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
CVEID: CVE-2023-50387
https://vulners.com/cve/CVE-2023-50387
DESCRIPTION: ISC BIND is vulnerable to a denial of service, caused by an
error when processing responses coming from specially crafted
DNSSEC-signed zones. By flooding the target server with queries, a
remote attacker could exploit this vulnerability to cause CPU
exhaustion on a DNSSEC-validating resolver.
CVSS Base Score: 7.5
CVSS Temporal Score: See
https://exchange.xforce.ibmcloud.com/vulnerabilities/281081
for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
CVEID: CVE-2023-4408
https://vulners.com/cve/CVE-2023-4408
DESCRIPTION: ISC BIND is vulnerable to a denial of service, caused by an
error when parsing large DNS messages. By flooding the target server
with queries, a remote attacker could exploit this vulnerability to
cause excessive CPU load.
CVSS Base Score: 7.5
CVSS Temporal Score: See
https://exchange.xforce.ibmcloud.com/vulnerabilities/282906
for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
CVEID: CVE-2023-6516
https://vulners.com/cve/CVE-2023-6516
DESCRIPTION: ISC BIND is vulnerable to a denial of service, caused by an
out-of-memory condition. By using specific recursive query patterns, a
remote attacker could exploit this vulnerability to cause the amount of
memory used by a named resolver to go well beyond the configured
max-cache-size limit, leading to a denial of service.
CVSS Base Score: 7.5
CVSS Temporal Score: See
https://exchange.xforce.ibmcloud.com/vulnerabilities/282902
for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
CVEID: CVE-2023-5679
https://vulners.com/cve/CVE-2023-5679
DESCRIPTION: ISC BIND is vulnerable to a denial of service, caused by an
error when enabling both DNS64 and serve-stale. By querying a
DNS64-enabled resolver for domain names triggering serve-stale, a
remote attacker could exploit this vulnerability to trigger an
assertion failure.
CVSS Base Score: 7.5
CVSS Temporal Score: See
https://exchange.xforce.ibmcloud.com/vulnerabilities/282904
for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
CVEID: CVE-2023-5517
https://vulners.com/cve/CVE-2023-5517
DESCRIPTION: ISC BIND is vulnerable to a denial of service, caused by a
flaw in query-handling code. By querying RFC 1918 reverse zones, a
remote attacker could exploit this vulnerability to trigger an
assertion failure.
CVSS Base Score: 7.5
CVSS Temporal Score: See
https://exchange.xforce.ibmcloud.com/vulnerabilities/282905
for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/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 7.1.916.2604 key_w_fs
bind.rte 7.2.916.0 7.2.916.2600 key_w_fs
bind.rte 7.3.916.0 7.3.916.2601 key_w_fs
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_fix26.tar
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_fix26.tar
For AIX 7.2 and VIOS 3.1 with OpenSSL 1.0 installed:
tar xvf bind_fix26/71bind916.tar
For AIX 7.2 and VIOS 3.1 with OpenSSL 1.1 installed:
tar xvf bind_fix26/72bind916.tar
For AIX 7.3 and VIOS 4.1:
tar xvf bind_fix26/73bind916.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
---------------------------------------------------------------------------------------
1a44cbf3ada06c29efdaad7757ab248995e0623689a5ca8682e4c610cd127364 71bind.rte key_w_csum
4016a2ffafda43b8deb9039dd6736a1b9bf3eb11afba0889041ae2e00dec5237 72bind.rte key_w_csum
4ed621e5f8957739023e370e04ef58bf38ee96489c6ba0f54181b40bcf239b8c 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_advisory26.asc.sig
C. 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_advisory26.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/7156443
ACKNOWLEDGEMENTS:
None.
CHANGE HISTORY:
First Issued: Tue Jun 4 16:06:25 CDT 2024
| Updated: Wed Jun 5 08:17:08 CDT 2024
| Update: Corrected the affected fileset levels to reflect that
| bind.rte 7.1.916.2604 and 7.3.916.2601 are vulnerable.
===============================================================================
*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.
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
AI Score
Confidence
High
EPSS
Percentile
92.9%