Security Bulletin
Summary
AIX is vulnerable to arbitrary code execution (CVE-2021-20271), RPM database corruption (CVE-2021-3421), and denial of service (CVE-2021-20266) due to RPM. RPM is used by AIX for package management.
Vulnerability Details
CVEID: CVE-2021-20271
DESCRIPTION: RPM could allow a remote attacker to execute arbitrary code on the system, caused by a flaw in the signature check function. By persuading a victim to open a specially-crafted package file, an attacker could exploit this vulnerability to cause RPM database corruption and execute arbitrary code on the system.
CVSS Base score: 6.7
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/198961 for the current score.
CVSS Vector: (CVSS:3.0/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H)
CVEID: CVE-2021-3421
DESCRIPTION: RPM Project RPM could allow a remote attacker to bypass security restrictions, caused by a flaw in the read function. By persuading a victim to install a seemingly verifiable package or compromise an RPM repository, an attacker could exploit this vulnerability to cause a corruption to the RPM database.
CVSS Base score: 6.1
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/203124 for the current score.
CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:L)
CVEID: CVE-2021-20266
DESCRIPTION: RPM Project RPM is vulnerable to a denial of service, caused by an out-of-bounds read flaw in the hdrblobInit function in lib/header.c. By sending a specially-crafted request, a local authenticated attacker could exploit this vulnerability to cause a denial of service condition.
CVSS Base score: 3.1
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/201041 for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L)
DESCRIPTION: RPM could allow a remote attacker to execute arbitrary code on the system, caused by a flaw in the signature check function. By persuading a victim to open a specially-crafted package file, an attacker could exploit this vulnerability to cause RPM database corruption and execute arbitrary code on the system.
CVSS Base score: 6.7
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/198961 for the current score.
CVSS Vector: (CVSS:3.0/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H)
CVEID: CVE-2021-3421
DESCRIPTION: RPM Project RPM could allow a remote attacker to bypass security restrictions, caused by a flaw in the read function. By persuading a victim to install a seemingly verifiable package or compromise an RPM repository, an attacker could exploit this vulnerability to cause a corruption to the RPM database.
CVSS Base score: 6.1
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/203124 for the current score.
CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:L)
CVEID: CVE-2021-20266
DESCRIPTION: RPM Project RPM is vulnerable to a denial of service, caused by an out-of-bounds read flaw in the hdrblobInit function in lib/header.c. By sending a specially-crafted request, a local authenticated attacker could exploit this vulnerability to cause a denial of service condition.
CVSS Base score: 3.1
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/201041 for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L)
Affected Products and Versions
| Affected Product(s) | Version(s) |
| AIX | 7.1 |
| AIX | 7.2 |
| AIX | 7.3 |
| VIOS | 3.1 |
The following fileset levels are vulnerable:
| Fileset | Lower Level | Upper Level |
| rpm.rte | 4.0.0.0 | 4.15.1.1005 |
| rpm.rte | 4.15.1.2000 | 4.15.1.2005 |
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 rpm.rte
Remediation/Fixes
A. FIXES
IBM strongly recommends addressing the vulnerability now.
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 | Fix |
| 7.1, 7.2 | rpm.rte.4.15.1.1006 |
| 7.3 | rpm.rte.4.15.1.2006 |
| VIOS Level | Fix |
| 3.1 | rpm.rte.4.15.1.1006 |
To extract the fixes from the tar file:
tar xvf rpm_fix.tar
cd rpm_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 |
| f12ab2fa1cce9129dc27f2d8a6af1f3e5a1075c93da87ff5f67519d19cfd8db1 | rpm.rte.4.15.1.1006 |
| 942c99ecb388645676e3f9361b0157406997188f4249ff7d07ee58bf3271cc34 | rpm.rte.4.15.1.2006 |
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:
B. 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 the fix installation:
For AIX 7.1 and 7.2:
installp -apYd . rpm.rte 4.15.1.1006
For AIX 7.3:
installp -apYd . rpm.rte 4.15.1.2006
To install the fix package:
For AIX 7.1 and 7.2:
installp -aXYd . rpm.rte 4.15.1.1006
For AIX 7.3:
installp -aXYd . rpm.rte 4.15.1.2006
Workarounds and Mitigations
None
Get Notified about Future Security Bulletins
References
Off
Change History
22 Sep 2022: 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
Review the IBM security bulletin disclaimer and definitions regarding your responsibilities for assessing potential impact of security vulnerabilities to your environment.
Document Location
Worldwide
[{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SWG10","label":"AIX"},"Component":"","Platform":[{"code":"PF002","label":"AIX"}],"Version":"7.1,7.2,7.3","Edition":"","Line of Business":{"code":"LOB08","label":"Cognitive Systems"}},{"Type":"MASTER","Line of Business":{"code":"LOB57","label":"Power"},"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SSPHKW","label":"PowerVM Virtual I\/O Server"},"ARM Category":[],"Platform":[{"code":"PF002","label":"AIX"}],"Version":"All Versions"}]
Was this topic helpful?
Document Information
Modified date:
23 September 2022
UID
ibm16823145