Summary
PocketMine-MP allows malicious client data to waste server resources due to lack of limits for explode()
Workarounds
No simple way to fix this.
Given that sign editing is the easiest way this could be exploited, workarounds could include plugins pre-processing BlockActorDataPacket to check that the incoming text doesn't have more than 4 parts when split by \n.
Impact
Due to lack of limits by default in the explode() function, malicious clients were able to abuse some packets to waste server CPU and memory.
This is similar to a previous security issue published in https://github.com/pmmp/PocketMine-MP/security/advisories/GHSA-gj94-v4p9-w672, but with a wider impact, including but not limited to:
- Sign editing
- LoginPacket JWT parsing
- Command parsing
However, the estimated impact of these issues is low, due to other limits such as the packet decompression limit.
The application allocates resources such as memory, threads, or file descriptors based on untrusted input without enforcing a cap. Typical impact: resource exhaustion leading to denial of service.
GHSA-G274-C6JJ-H78P has a CVSS score of 5.3 (Medium). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (5.25.2); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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The issue was fixed in 5.25.2 via d0d84d4c5195fb0a68ea7725424fda63b85cd831.
A custom PHPStan rule has also been introduced to the project, which will henceforth require that all calls to explode() within the codebase must specify the limit parameter.
Frequently Asked Questions
- What is GHSA-G274-C6JJ-H78P? GHSA-G274-C6JJ-H78P is a medium-severity allocation of resources without limits or throttling vulnerability in pocketmine/pocketmine-mp (composer), affecting versions < 5.25.2. It is fixed in 5.25.2. The application allocates resources such as memory, threads, or file descriptors based on untrusted input without enforcing a cap.
- How severe is GHSA-G274-C6JJ-H78P? GHSA-G274-C6JJ-H78P has a CVSS score of 5.3 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of pocketmine/pocketmine-mp are affected by GHSA-G274-C6JJ-H78P? pocketmine/pocketmine-mp (composer) versions < 5.25.2 is affected.
- Is there a fix for GHSA-G274-C6JJ-H78P? Yes. GHSA-G274-C6JJ-H78P is fixed in 5.25.2. Upgrade to this version or later.
- Is GHSA-G274-C6JJ-H78P exploitable, and should I be worried? Whether GHSA-G274-C6JJ-H78P is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether GHSA-G274-C6JJ-H78P is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix GHSA-G274-C6JJ-H78P? Upgrade
pocketmine/pocketmine-mpto 5.25.2 or later.