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GHSA-g274-c6jj-h78p CVE-2025-71418

PocketMine-MP allows malicious client data to waste server resources due to lack of limits for explode()

Medium Packagist
Severity
6.9 / 10
Medium · CVSS 4.0
Exploit chance (EPSS)
0.55%
Chance of exploitation in the next 30 days. Higher than 45.83% of scored vulnerabilities.
Known exploited
No
Not in CISA's catalog
Weakness
CWE-770 Allocation of Resources Without Limits or Throttling
Fix
5.25.2
Upgrade pocketmine/pocketmine-mp to this version or later

Description

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.

Patches

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.

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.

Affected versions

Packagist

PackageVulnerableFixed in
pocketmine/pocketmine-mp
< 5.25.2
5.25.2

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

pocketmine/pocketmine-mp Packagist → 5.25.2

composer
composer require pocketmine/pocketmine-mp:^5.25.2

Severity breakdown

CVSS 4.0 6.9

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Attack vector
Network
Attack complexity
Low
Attack requirements
None
Privileges required
None
User interaction
None
Confidentiality (vulnerable system)
None
Integrity (vulnerable system)
None
Availability (vulnerable system)
Low
Confidentiality (subsequent systems)
None
Integrity (subsequent systems)
None
Availability (subsequent systems)
None
Exploit maturity
Not defined
Scope
X

CVSS 3.1 5.3

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
Low

Weakness

CWE-770: Allocation of Resources Without Limits or Throttling

The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.

How to prevent it
  • Requirements: Clearly specify the minimum and maximum expectations for capabilities, and dictate which behaviors are acceptable when resource allocation reaches limits.
  • Architecture and Design: Limit the amount of resources that are accessible to unprivileged users. Set per-user limits for resources. Allow the system administrator to define these limits. Be careful to avoid CWE-410.
  • Architecture and Design: Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended. A strong authentication and access control model will help prevent such attacks from occurring in the first place, and it will help the administrator to identify who is committing the abuse. The login application should be protected against DoS attacks as much as possible. Limiting the database access, perhaps by caching result sets, can help minimize the resources expended. To further limit the potential for a DoS attack, consider tracking the rate of requests received from users and blocking requests that exceed a defined rate threshold.
  • Implementation: Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
  • Architecture and Design: For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
  • Architecture and Design: Mitigation of resource exhaustion attacks requires that the target system either: recognizes the attack and denies that user further access for a given amount of time, typically by using increasing time delays uniformly throttles all requests in order to make it more difficult to consume resources more quickly than they can again be freed. The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question. The second solution can be difficult to effectively institute -- and even when properly done, it does not provide a full solution. It simply requires more resources on the part of the attacker.
  • Architecture and Design: Ensure that protocols have specific limits of scale placed on them.
  • Architecture and Design, Implementation: If the program must fail, ensure that it fails gracefully (fails closed). There may be a temptation to simply let the program fail poorly in cases such as low memory conditions, but an attacker may be able to assert control before the software has fully exited. Alternately, an uncontrolled failure could cause cascading problems with other downstream components; for example, the program could send a signal to a downstream process so the process immediately knows that a problem has occurred and has a better chance of recovery. Ensure that all failures in resource allocation place the system into a safe posture.
  • Operation, Architecture and Design: Use quotas or other resource-limiting settings provided by the operating system or environment. For example, when managing system resources in POSIX, setrlimit() can be used to set limits for certain types of resources, and getrlimit() can determine how many resources are available. However, these functions are not available on all operating systems. When the current levels get close to the maximum that is defined for the application (see CWE-770), then limit the allocation of further resources to privileged users; alternately, begin releasing resources for less-privileged users. While this mitigation may protect the system from attack, it will not necessarily stop attackers from adversely impacting other users. Ensure that the application performs the appropriate error checks and error handling in case resources become unavailable (CWE-703).

References

Timeline

  1. Published
  2. Last updated by the source
  3. Latest EPSS score
AdvisorySeverityWhy it's related
GHSA-pg53-p7qp-65cv
PocketMine-MP has potential memory/network vulnerability from repeated ResourcePackClientResponsePacket packets
Low Also affects pocketmine/pocketmine-mp
GHSA-xp4f-g2cm-rhg7
PocketMine-MP has LogDoS by many junk properties in client data JWT in LoginPacket
Medium Also affects pocketmine/pocketmine-mp
GHSA-f9jp-856v-8642
PocketMine-MP: Player entities can still die and drop items in flaggedForDespawn state
Medium Also affects pocketmine/pocketmine-mp
GHSA-7hmv-4j2j-pp6f
PocketMine-MP: Network amplification vulnerability with `ActorEventPacket`
Medium Also affects pocketmine/pocketmine-mp
GHSA-788v-5pfp-93ff
PocketMine-MP: JSON decoding of unlimited size large arrays/objects in ModalFormResponse Handling
Medium Also affects pocketmine/pocketmine-mp
GHSA-h6rj-3m53-887h
PocketMine-MP: LogDoS by large complex unknown property logging in clientData in LoginPacket
High Also affects pocketmine/pocketmine-mp
GHSA-fqqv-56h5-f57g
PocketMine-MP `ResourcePackDataInfoPacket` amplification vulnerability due to lack of resource pack sequence status checking
Medium Also affects pocketmine/pocketmine-mp
GHSA-h6j3-j35f-v2x7
PocketMine-MP server crash with certain invalid JSON payloads in `LoginPacket` due to dependency vulnerability (3rd time)
High Also affects pocketmine/pocketmine-mp
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