Skip to content

Improperly checked metadata on tools/armour itemstacks received from the client

High
dktapps published GHSA-46c5-pfj8-fv65 Mar 18, 2022

Package

composer pocketmine/pocketmine-mp (Composer)

Affected versions

< 4.2.3

Patched versions

4.2.4

Description

Impact

Due to a workaround applied in 1.13, an attacker may send a negative damage/meta value in a tool or armour item's NBT, which TypeConverter then blindly uses as if it was valid without being checked.

When this invalid metadata value reaches Durable->setDamage(), an exception is thrown because the metadata is not within the expected range for damage values.

This can be reproduced with either a too-large damage value, or a negative one.

Patches

c8e1cfc

Workarounds

In theory this can be checked by plugins using a custom TypeConverter, but this is likely to be very cumbersome.

For more information

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

CVE ID

No known CVE

Weaknesses

No CWEs

Credits