[ZBX-20383] Possible remote code execution in Zabbix Java Gateway with logback 1.2.7 and prior versions (no CVE registered) Created: 2021 Dec 16  Updated: 2024 Oct 22  Resolved: 2022 Jun 22

Status: Closed
Project: ZABBIX BUGS AND ISSUES
Component/s: Java gateway (J)
Affects Version/s: None
Fix Version/s: 4.0.37rc1, 5.0.19rc2, 5.4.9rc2, 6.0.0beta2, 6.0 (plan)

Type: Defect (Security) Priority: Critical
Reporter: Vladislavs Sokurenko Assignee: Vladislavs Sokurenko
Resolution: Fixed Votes: 0
Labels: security-vulnerabilities
Remaining Estimate: Not Specified
Time Spent: Not Specified
Original Estimate: Not Specified

Issue Links:
Causes
caused by ZBXNEXT-555 remote monitoring of jmx applications Closed
Duplicate
Team: Team A
Sprint: Sprint 83 (Dec 2021), Sprint 84 (Jan 2022), Sprint 85 (Feb 2022), Sprint 86 (Mar 2022), Sprint 87 (Apr 2022), Sprint 88 (May 2022), Sprint 89 (Jun 2022)
Story Points: 0.5

 Description   
CVE number no CVE registered
CVSS score -
Severity Medium
Affected versions 2.0-2.X
3.0-3.X
4.0.0 - 4.0.36
5.0.18
5.4.0 -5.4.8
6.0.0alpha1-6.0.0beta1
Description In Zabbix Java Gateway with logback version 1.2.7 and prior versions, an attacker with the required privileges to edit configurations files could craft a malicious configuration allowing to execute arbitrary code loaded from LDAP servers.
Known attack vectors A successful RCE attack with CVE-2021-42550 requires all of the following conditions to be met: write access to zabbix_java_gateway_logback.xml; use of logback versions < 1.2.9; reloading of poisoned configuration data, which implies application restart or scan="true" set prior to the attack. An attacker with such privileges may get remote access to the server with Zabbix Java Gateway
Resolution To remediate CVE-2021-42550 apply the updates listed in the 'Fixed Version' section to appropriate products or if an immediate update is not possible, follow the presented below workarounds.
As an additional measure for the fixed versions, we also recommend checking permission to /etc/zabbix/zabbix_java_gateway_logback.xml file and set it read-only, if write permissions are available for “zabbix” user. 
Workarounds If an immediate update is not possible, check permissions for “zabbix” user:
  • /etc/zabbix/zabbix_java_gateway_logback.xml file permissions are set to read-only only;
  • the user cannot restart Zabbix Java Gateway service.


 Comments   
Comment by Vladislavs Sokurenko [ 2021 Dec 16 ]

Fixed in pull request feature/DEV-2031-4.0

Comment by Vladislavs Sokurenko [ 2021 Dec 17 ]

Fixed in:

Updated documentation:

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