Cloud Vulnerability DB
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Vulnerability DatabaseCVE-2025-27533
CVE-2025-27533:
Java vulnerability analysis and mitigation
Overview
A Memory Allocation with Excessive Size Value vulnerability has been identified in Apache ActiveMQ, tracked as CVE-2025-27533. The vulnerability was discovered and disclosed on May 6, 2025, affecting multiple versions of Apache ActiveMQ: 6.0.0 before 6.1.6, 5.18.0 before 5.18.7, 5.17.0 before 5.17.7, and versions before 5.16.8. Notably, ActiveMQ version 5.19.0 is not affected by this vulnerability (OpenWall, SecurityOnline).
Technical details
The vulnerability stems from improper validation of buffer size values during the unmarshalling of OpenWire commands. This oversight in input validation could lead to excessive memory allocation when processing specially crafted messages. The issue has been assigned a CVSS 4.0 Base Score of 6.9 (MEDIUM) with the vector string CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/AU:Y/R:A/V:D/RE:M/U:Red. The vulnerability is classified under CWE-789: Memory Allocation with Excessive Size Value (NVD).
Impact
The primary impact of this vulnerability is the potential for denial of service (DoS) attacks through process memory depletion. When exploited, it can affect applications and services that depend on the availability of the ActiveMQ broker, particularly in environments not using mutual TLS connections. This can lead to service disruption and system unavailability (OpenWall, SecurityOnline).
Mitigation and workarounds
Apache has released patched versions to address this vulnerability. Users are strongly recommended to upgrade to version 6.1.6+, 5.19.0+, 5.18.7+, 5.17.7, or 5.16.8. For environments unable to upgrade immediately, implementing mutual TLS on ActiveMQ brokers serves as an effective mitigation measure (OpenWall).
Additional resources
Source: This report was generated using AI
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