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Denial-of-service by sending large modal form responses

Moderate
dktapps published GHSA-7m9r-rq9j-wmmh Jan 9, 2023

Package

composer pocketmine/pocketmine-mp (Composer)

Affected versions

< 4.12.5

Patched versions

4.12.5

Description

Impact

Due to a workaround for an old client bug (which has since been fixed), very large JSON payloads in ModalFormResponsePacket were able to cause the server to spend a significant amount of time processing the packet. Large numbers of these packets were able to hog CPU time so as to prevent the server from processing other connections in a timely manner.

Patches

The problem has been addressed in 3baa5ab by removing the workaround code.

Workarounds

Plugins could cancel DataPacketReceiveEvent for this packet, decode the data their way, and then call Player->onFormSubmit() directly, bypassing the vulnerable code.

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

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

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

CVE ID

No known CVE

Weaknesses

Credits