CVE-2025-71417 in PocketMine-MP
Summary
by MITRE • 09/09/2026
PocketMine-MP before 5.32.1 fails to validate uniqueness of pack UUIDs in ResourcePackClientResponsePacket STATUS_SEND_PACKS handling, allowing authenticated clients to trigger duplicate pack transmissions. Attackers can send multiple copies of valid pack UUIDs in a single packet to exhaust server memory and cause denial of service.
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Analysis
by VulDB Data Team • 09/09/2026
The vulnerability identified in PocketMine-MP versions prior to 5.32.1 represents a critical flaw within the resource pack handling subsystem, specifically located in the processing logic for ResourcePackClientResponsePacket STATUS_SEND_PACKS messages. This component is responsible for managing the distribution of custom texture and sound packs to connected players during gameplay sessions. The core technical deficiency lies in the absence of strict validation mechanisms designed to ensure the uniqueness of package identifiers within a single transmission request. When an authenticated client initiates this process, the server-side implementation fails to check whether multiple entries within the packet contain identical Universal Unique Identifiers (UUIDs). This oversight allows malicious actors or compromised clients to construct and transmit packets containing duplicate pack UUIDs in rapid succession or bundled together, effectively bypassing standard integrity checks that would normally prevent redundant data processing.
From an operational perspective, this lack of validation leads directly to a severe denial of service condition through resource exhaustion. As the server processes each entry in the packet independently without deduplication logic, it allocates memory and computational resources for every instance of the pack UUID provided by the client. An attacker can exploit this behavior by sending a single malformed packet containing hundreds or thousands of duplicate entries. The server is forced to load these redundant references into its active memory pool, leading to rapid consumption of available RAM. This uncontrolled allocation causes the server process to become increasingly sluggish and eventually crash due to out-of-memory errors, rendering the Minecraft multiplayer environment unavailable for all connected users. The impact is particularly acute because it requires only authenticated access, which is standard for most private servers where players are expected to have valid accounts.
This vulnerability aligns with CWE-20 Improper Input Validation, as the application fails to verify that the input data adheres to the expected structural constraints regarding unique identifiers. Furthermore, it can be classified under CWE-400 Uncontrolled Resource Consumption, given that the flaw directly results in excessive resource usage leading to service disruption. In terms of offensive security frameworks such as MITRE ATT&CK, this exploit technique corresponds to T1498 Network Denial of Service, specifically leveraging application layer protocols to exhaust server resources rather than relying on volumetric network flooding. The attack vector is remote and requires authentication, placing it in the category of authenticated attacks that target specific protocol implementations within game servers.
To mitigate this vulnerability, immediate patching to version 5.32.1 or later is required, as these versions include fixes for the packet handling logic. Server administrators should ensure their infrastructure runs updated software releases provided by the PocketMine-MP development team. In environments where upgrading may not be immediately feasible, implementing network-level rate limiting on resource pack request packets can help mitigate the impact of such attacks by restricting the frequency and size of incoming STATUS_SEND_PACKS messages. Additionally, deploying intrusion detection systems capable of identifying anomalous packet structures with repeated identifiers can provide an additional layer of defense against automated exploitation attempts targeting this specific flaw in older server builds.