IBM Support

Security Bulletin: Vulnerability in lpd affects AIX (CVE-2021-29693)

Security Bulletin


There is a vulnerability in the lpd daemon that affects AIX.

Vulnerability Details

CVEID:   CVE-2021-29693
DESCRIPTION:   IBM AIX could allow a local user with elevated group privileges to exploit a vulnerability in the lpd daemon.
CVSS Base score: 4.9
CVSS Temporal Score: See: for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H)

Affected Products and Versions

Affected Product(s) Version(s)
AIX 7.1
AIX 7.2
VIOS 3.1

The vulnerabilities in the following filesets are being addressed:

Fileset Lower Level Upper Level
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 bos.rte.printers



IBM has assigned the following APARs to this problem:

7.1.5 IJ30372 SP08
7.2.3 IJ30799 SP07
7.2.4 IJ30800 SP04
7.2.5 IJ30447 SP02

3.1.0 IJ30799
3.1.1 IJ30800
3.1.2 IJ30447
Subscribe to the APARs here:
By subscribing, you will receive periodic email alerting you to the status of the APAR, and a link to download the fix once it becomes available.
AIX and VIOS fixes are available.
The AIX and VIOS fixes can be downloaded via ftp or http from:
The link above is to a tar file containing this signed advisory, fix 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.
AIX Level Interim Fix (*.Z) IJ30372s5a.210210.epkg.Z IJ30372s5a.210210.epkg.Z IJ30799s4a.210209.epkg.Z IJ30799s4a.210209.epkg.Z IJ30800s1a.210210.epkg.Z IJ30800s1a.210210.epkg.Z IJ30447s1a.210210.epkg.Z IJ30447s1a.210210.epkg.Z
Please note that the above table refers to AIX TL/SP level as opposed to fileset level, i.e., is AIX 7200-03-05.
Please reference the Affected Products and Version section above for help with checking installed fileset levels.
VIOS Level Interim Fix (*.Z) IJ30799s4a.210209.epkg.Z IJ30799s4a.210209.epkg.Z IJ30800s1a.210210.epkg.Z IJ30800s1a.210210.epkg.Z IJ30800s1a.210210.epkg.Z IJ30800s1a.210210.epkg.Z IJ30447s1a.210210.epkg.Z IJ30447s1a.210210.epkg.Z
To extract the fixes from the tar file:
tar xvf lpd_fix.tar
cd lpd_fix
Verify you have retrieved the fixes intact:
The checksums below were generated using the "openssl dgst -sha256 [filename]" command as the following:
openssl dgst -sha256 filename
9c7a7c2ed532dd5674678376de5a7eac561f328590d0ebb32ed3b3736adbc406 IJ30372s5a.210210.epkg.Z
85330debf467d4f93a24a2d58879a4c6a5b79fff7090babe709344de03a5f234 IJ30447s1a.210210.epkg.Z
08cb64dea4738e112bbe864b877e3cdabbb3f719c14fa7e2345b0cee94073848 IJ30799s4a.210209.epkg.Z
eee3dc370a4467031c6809d261f040ab7ae58e7288146541f1a43edbd5779e09 IJ30800s1a.210210.epkg.Z
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 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:
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:
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


Get Notified about Future Security Bulletins



Change History

25 June 2021: 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.


Review the IBM security bulletin disclaimer and definitions regarding your responsibilities for assessing potential impact of security vulnerabilities to your environment.

Document Location


[{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SWG10","label":"AIX"},"Component":"","Platform":[{"code":"PF002","label":"AIX"}],"Version":"7.1,7.2","Edition":"","Line of Business":{"code":"LOB08","label":"Cognitive Systems"}},{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SWG10","label":"AIX"},"Component":"","Platform":[{"code":"PF002","label":"AIX"}],"Version":"7.2","Edition":"","Line of Business":{"code":"LOB08","label":"Cognitive Systems"}},{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SWG10","label":"AIX"},"Component":"","Platform":[{"code":"PF002","label":"AIX"}],"Version":"7.1","Edition":"","Line of Business":{"code":"LOB08","label":"Cognitive Systems"}},{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SSPHKW","label":"PowerVM Virtual I\/O Server"},"Component":"","Platform":[{"code":"PF002","label":"AIX"}],"Version":"3.1","Edition":"","Line of Business":{"code":"LOB57","label":"Power"}}]

Document Information

Modified date:
20 October 2021