CVE-2020-4270: 
IBM QRadar SIEM vulnerability analysis and mitigation

IBM QRadar versions 7.3.0 to 7.3.3 Patch 2 contained a local privilege escalation vulnerability (CVE-2020-4270) discovered in September 2019. The vulnerability allowed local users to gain escalated privileges due to weak file permissions in the system (IBM Security, Full Disclosure).

The vulnerability exists due to insecure file permissions on the /opt/qvm/iem/bin/run-result-reader.sh script, which is owned by the nobody user but executed by root's crontab every 20 minutes. This configuration allows any process running as the nobody user to modify the script and add commands that would be executed with root privileges. The vulnerability has a CVSS Base score of 8.4 (CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) (IBM Security, Full Disclosure).

The vulnerability allows local users to gain root privileges and full control of the QRadar system. When combined with a code execution vulnerability in QRadar's web application, attackers could potentially escalate their privileges to gain complete system access (Full Disclosure).

The vulnerability can be exploited by any process running as the nobody user, which includes QRadar's web application. The exploit involves modifying the run-result-reader.sh script to include malicious commands that will be executed with root privileges when the script is run by the root user's crontab (Full Disclosure).

IBM has released fixed versions including QRadar 7.4.0 GA, QRadar 7.3.3 Patch 3, and QRadar 7.3.2 Patch 7. No workarounds are available for this vulnerability, making it essential to upgrade to a patched version (IBM Security).