GHSA-gj94-v4p9-w672: Pocketmine/pocketmine mp Denial-of-service Vulnerability Processing Large Chat Vulnerability

MODERATE
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CVSS 5.3
Published
Advisory Summary

GHSA-gj94-v4p9-w672 is a MODERATE (CVSS 5.3) denial-of-service vulnerability processing large chat vulnerability (General Security Weakness) affecting Pocketmine/pocketmine mp libraries in the Packagist ecosystem. The issue involves denial-of-service vulnerability processing large chat messages containing many newlines. Remediation is available by upgrading affected packages to version 4.2.10.

GHSA-gj94-v4p9-w672 at a Glance

CVE Identifier N/A
GHSA Identifier GHSA-gj94-v4p9-w672
Severity MODERATE
CVSS v3.1 Base Score 5.3
CWE Classification General Security Weakness
Affected Product Pocketmine/pocketmine mp
Package Ecosystem Packagist
Published Date
Last Updated

Security Impact

CVSS: 5.3

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability Low (A:L)

How to Fix GHSA-gj94-v4p9-w672

To remediate this vulnerability, upgrade all affected Pocketmine/pocketmine mp dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

pocketmine/pocketmine-mp fixed: 4.2.10 
Upgrade pocketmine/pocketmine-mp to 4.2.10
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for pocketmine/pocketmine-mp

How to Check if You Are Affected

To determine whether your application is affected by GHSA-gj94-v4p9-w672, inspect your project dependencies for Pocketmine/pocketmine mp:

inspect dependencies for pocketmine/pocketmine-mp

Analyze the terminal output to locate any version of Pocketmine/pocketmine mp in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 4.2.10), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under General Security Weakness. In Pocketmine/pocketmine mp, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Impact PocketMine-MP caps maximum chat message length at 512 Unicode characters, or about 2048 bytes. No more than 2 chat messages may be sent per tick. However, due to legacy reasons, incoming chat message blobs are split by `\n`, and each part is treated as a separate message, the length of each part is individually checked. The length of the whole message is not checked. This leads to an exploitable performance issue, in which a malicious client may send a chat packet of several megabytes containing nothing but `\n` newline characters. The server will parse this into a very large array and spend a long time (several milliseconds) iterating over it for no reason. Furthermore, due to the lack of sufficient rate limit checks before parsing messages, malicious clients may bombard the server with many thousands of these malicious messages, causing lockups for a significant amount of time (seconds or minutes). ### Patches This bug was addressed in https://github.com/pmmp/PocketMine-MP/commit/df33e179e5d3ff13b56a2d7060bf592b0f797258 by: - checking the length of the incoming message as a whole before parsing it - it may not be larger than `messageCounter * maxChatMessageSize` (`messageCounter` is decremented once for every message sent) - limiting the maximum number of times a message may be split on newlines before giving up and discarding the message (maximum 3 parts; anything after the first 2 parts is discarded) ### Workarounds Handle `DataPacketReceiveEvent` and check for these excessive newlines in incoming `TextPacket`. ### For more information If you have any questions or comments about this advisory: * Email us at [team@pmmp.io](mailto:team@pmmp.io)

GHSA-gj94-v4p9-w672 Affected Pocketmine/pocketmine mp Versions

1 component(s)
Fixed Versions:
4.2.10
Product / Package Ecosystem Affected Versions Fixed Version
pocketmine/pocketmine-mp
 Packagist
< 4.2.10
4.2.10

References

GitHub Advisory / Wiki ADVISORY
https://github.com/pmmp/PocketMine-MP/security/advisories/GHSA-gj94-v4p9-w672
Pocketmine/pocketmine mp Source Repository REPOSITORY
https://github.com/pmmp/PocketMine-MP

Frequently Asked Questions

What is GHSA-gj94-v4p9-w672?
GHSA-gj94-v4p9-w672 is a security vulnerability in Pocketmine/pocketmine mp involving Denial-of-service vulnerability processing large chat messages containing many newlines under General Security Weakness.
Which Pocketmine/pocketmine mp versions are affected?
Affected versions include releases prior to 4.2.10 across affected packages: pocketmine/pocketmine-mp.
What version fixes GHSA-gj94-v4p9-w672?
Upgrading to 4.2.10 (or the latest patched release for your respective branch) resolves the vulnerability.
Is pocketmine/pocketmine-mp affected?
Yes, pocketmine/pocketmine-mp is affected in releases prior to 4.2.10. Upgrade your dependency to 4.2.10 or later.
What is the CVSS score of GHSA-gj94-v4p9-w672?
GHSA-gj94-v4p9-w672 has a CVSS v3.1 base score of 5.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
What CWE is associated with GHSA-gj94-v4p9-w672?
GHSA-gj94-v4p9-w672 is classified under General Security Weakness.
How can I check Packagist dependencies for GHSA-gj94-v4p9-w672?
Run the dependency tree command: 'inspect dependencies for pocketmine/pocketmine-mp'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-gj94-v4p9-w672",
  "modified" : "2025-12-26T17:29:04Z",
  "published" : "2022-05-25T22:34:01Z",
  "aliases" : [ ],
  "summary" : "Denial-of-service vulnerability processing large chat messages containing many newlines",
  "details" : "### Impact\nPocketMine-MP caps maximum chat message length at 512 Unicode characters, or about 2048 bytes. No more than 2 chat messages may be sent per tick. However, due to legacy reasons, incoming chat message blobs are split by `\\n`, and each part is treated as a separate message, the length of each part is individually checked. The length of the whole message is not checked.\n\nThis leads to an exploitable performance issue, in which a malicious client may send a chat packet of several megabytes containing nothing but `\\n` newline characters. The server will parse this into a very large array and spend a long time (several milliseconds) iterating over it for no reason.\n\nFurthermore, due to the lack of sufficient rate limit checks before parsing messages, malicious clients may bombard the server with many thousands of these malicious messages, causing lockups for a significant amount of time (seconds or minutes).\n\n### Patches\nThis bug was addressed in https://github.com/pmmp/PocketMine-MP/commit/df33e179e5d3ff13b56a2d7060bf592b0f797258 by:\n- checking the length of the incoming message as a whole before parsing it - it may not be larger than `messageCounter * maxChatMessageSize` (`messageCounter` is decremented once for every message sent)\n- limiting the maximum number of times a message may be split on newlines before giving up and discarding the message (maximum 3 parts; anything after the first 2 parts is discarded)\n\n### Workarounds\nHandle `DataPacketReceiveEvent` and check for these excessive newlines in incoming `TextPacket`.\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Email us at [team@pmmp.io](mailto:team@pmmp.io)",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "pocketmine/pocketmine-mp"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "4.2.10"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/pmmp/PocketMine-MP/security/advisories/GHSA-gj94-v4p9-w672"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/pmmp/PocketMine-MP"
  } ],
  "database_specific" : {
    "cwe_ids" : [ ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-05-25T22:34:01Z",
    "nvd_published_at" : null
  }
}