Skip to content

NaN/INF in serverbound movement packets can crash clients and servers

High severity GitHub Reviewed Published May 19, 2021 in pmmp/PocketMine-MP • Updated Jan 9, 2023

Package

composer pocketmine/pocketmine-mp (Composer)

Affected versions

<= 3.18.0

Patched versions

3.18.1

Description

Impact

A malicious client may send a MovePlayerPacket to the server whose position or rotation contains NaN or INF. Since neither the server nor vanilla client handles this properly, a number of interesting side effects come into play.

  • The server may crash in various ways if this exploit is used, because some mathematical operations on NaN/INF generate PHP warnings, which are converted into exceptions.
  • Clients may not be able to see other clients who have a NaN/INF rotation.
  • Clients may also crash in such cases.

Patches

A patch for this was included in the 3.18.1 release: pmmp/PocketMine-MP@fb20bb3

Workarounds

Workarounds could be implemented as plugins using DataPacketReceiveEvent to block any inbound movement packets containing bogus values.

For more information

If you have any questions or comments about this advisory:

References

@dktapps dktapps published to pmmp/PocketMine-MP May 19, 2021
Reviewed May 21, 2021
Published to the GitHub Advisory Database Mar 18, 2022
Last updated Jan 9, 2023

Severity

High

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
High

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:H

Weaknesses

CVE ID

No known CVE

GHSA ID

GHSA-fm35-jgg3-3grx

Source code

No known source code
Loading Checking history
See something to contribute? Suggest improvements for this vulnerability.