Security Bulletin: Multiple vulnerabilities in Apache Log4j affects some features of IBM® Db2® (CVE-2021-45046, CVE-2021-45105)

Summary

Apache Log4j open source library used by IBM® Db2® is affected by multiple vulnerabilities that could allow a remote attacker to execute arbitrary code on the system or cause a denial of service. This library is used by the Db2 Federation feature. The fix for the vulnerability is to update the Apache Log4j library to 2.17.0. Please see CVE-2021-4104 for bulletin relating to Log4j V1. Please see CVE-2021-44832 and CVE-2021-44228 for bulletins relating to Log4j V2.

Vulnerability Details

CVEID:CVE-2021-45105
**DESCRIPTION:**Apache Log4j is vulnerable to a denial of service, caused by the failure to protect from uncontrolled recursion from self-referential lookups. A remote attacker with control over Thread Context Map (MDC) input data could craft malicious input data that contains a recursive lookup to cause a StackOverflowError that will terminate the process.
CVSS Base score: 7.5
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/215647 for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

CVEID:CVE-2021-45046
**DESCRIPTION:**Apache Log4j could result in remote code execution, caused by an incomplete fix of CVE-2021-44228 in certain non-default configurations. When the logging configuration uses a non-default Pattern Layout with a Context Lookup, an attacker with control over Thread Context Map (MDC) input data can craft malicious input data using a JNDI Lookup pattern to leak sensitive information and remote code execution in some environments and local code execution in all environments.
CVSS Base score: 9
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/215195 for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H)

Affected Products and Versions

Fix pack levels of IBM Db2 V11.5 for all editions on all platforms are affected only if the following features are configured:

Federation:

• DVM JDBC wrapper driver,
• NoSQL wrapper driver (for Hadoop),
• Blockchain wrapper driver (for Hyperledger Fabric, Linux 64-bit, x86-64 only)

IBM Db2 V9.7, V10.1, V10.5 and V11.1 are not affected. Please note that log4j v1.x was removed in a previous build, and customers are strongly recommended to apply those fixes if you are on an older version of Db2. See Security Bulletin for details.

To determine if Federation is enabled, issue the following:

db2 get dbm cfg | grep FEDERATED

If a value of NO is returned, you are not vulnerable.

You can determine if you are using one of the affected wrappers by performing:

To determine if the DVM JDBC wrapper is in use, issue the following statement:

db2 “select servername from syscat.serveroptions where option = ‘DRIVER_CLASS’ and setting = ‘com.rs.jdbc.dv.DvDriver’”

If a servername is returned, then you are using the DVM JDBC wrapper via the DvDriver class.

To determine if the NoSQL hadoop wrapper is in use, issue the following statement:

db2 “select * from syscat.servers where servertype = ‘HDFSPARQUET’”

If 1 or more rows are returned, then NoSQL hadoop wrapper is in use.

To determine if the NoSQL Blockchain wrapper is in use, issue the following statement:

db2 “select * from syscat.serveroptions where option=‘PEER_URL’”

If 1 or more rows are returned, then NoSQL Blockchain wrapper is in use.

Remediation/Fixes

Customers running any vulnerable fixpack level of an affected Program, V11.5, can download the special build containing the interim fix for this issue from Fix Central. These special builds are available based on the most recent fixpack level for the V11.5.6 and V11.5.7 release. They can be applied to any affected fixpack level of the appropriate release to remediate this vulnerability.

Note: These builds supersede the builds provided for resolution to CVE-2021-44228 and CVE-2021-4104

AIX 64-bit
Linux 32-bit, x86-32
Linux 64-bit, x86-64
Linux 64-bit, POWER™ little endian
Linux 64-bit, System z®, System z9® or zSeries®
Windows 32-bit, x86
Windows 64-bit, x86

V11.5| 11.5.8| IT39474| <https://www.ibm.com/support/pages/node/6830623&gt;

Workarounds and Mitigations

None.