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GHSA-wqqv-jcfr-9f5g CVE-2023-54396

PocketMine-MP has improperly handled dye colour IDs in banner NBT, leading to server crash

High Packagist
Severity
7.1 / 10
High · CVSS 4.0
Exploit chance (EPSS)
0.53%
Chance of exploitation in the next 30 days. Higher than 44.87% of scored vulnerabilities.
Known exploited
No
Not in CISA's catalog
Weakness
CWE-129 Improper Validation of Array Index
Fix
4.8.1
Upgrade pocketmine/pocketmine-mp to this version or later

Description

Impact

DyeColorIdMap->fromId() did not account for the possibility that it might be given invalid input. This means that an undefined offset error would occur whenever this happened.

This code is indirectly called during Banner->deserializeCompoundTag(), which is invoked when deserializing any item NBT, whether from network or disk.

An attacker could use this bug to crash a server by providing NBT with invalid values for pattern colours in an inventory transaction, or by using /give to obtain an item with NBT like this.

Patches

08b9495bce2d65a6d1d3eeb76e484499a00765eb

Workarounds

This is quite difficult to work around via a plugin. Theoretically, it's possible to override the Banner item class from a plugin and validate the data before it reaches deserializeCompoundTag().

For more information

If you have any questions or comments about this advisory:

Affected versions

Packagist

PackageVulnerableFixed in
pocketmine/pocketmine-mp
< 4.8.1
4.8.1

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 → 4.8.1

composer
composer require pocketmine/pocketmine-mp:^4.8.1

Severity breakdown

CVSS 4.0 7.1

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/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
Low
User interaction
None
Confidentiality (vulnerable system)
None
Integrity (vulnerable system)
None
Availability (vulnerable system)
High
Confidentiality (subsequent systems)
None
Integrity (subsequent systems)
None
Availability (subsequent systems)
None
Exploit maturity
Not defined
Scope
X

CVSS 3.1 7.5

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

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

Weakness

CWE-129: Improper Validation of Array Index

The product uses untrusted input when calculating or using an array index, but the product does not validate or incorrectly validates the index to ensure the index references a valid position within the array.

How to prevent it
  • Architecture and Design: Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
  • 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. Even though client-side checks provide minimal benefits with respect to server-side security, they are still useful. First, they can support intrusion detection. If the server receives input that should have been rejected by the client, then it may be an indication of an attack. Second, client-side error-checking can provide helpful feedback to the user about the expectations for valid input. Third, there may be a reduction in server-side processing time for accidental input errors, although this is typically a small savings.
  • Requirements: Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, Ada allows the programmer to constrain the values of a variable and languages such as Java and Ruby will allow the programmer to handle exceptions when an out-of-bounds index is accessed.
  • Operation, Build and Compilation: Run or compile the software using features or extensions that randomly arrange the positions of a program's executable and libraries in memory. Because this makes the addresses unpredictable, it can prevent an attacker from reliably jumping to exploitable code. Examples include Address Space Layout Randomization (ASLR) [REF-58] [REF-60] and Position-Independent Executables (PIE) [REF-64]. Imported modules may be similarly realigned if their default memory addresses conflict with other modules, in a process known as "rebasing" (for Windows) and "prelinking" (for Linux) [REF-1332] using randomly generated addresses. ASLR for libraries cannot be used in conjunction with prelink since it would require relocating the libraries at run-time, defeating the whole purpose of prelinking. For more information on these techniques see D3-SAOR (Segment Address Offset Randomization) from D3FEND [REF-1335].
  • Operation: Use a CPU and operating system that offers Data Execution Protection (using hardware NX or XD bits) or the equivalent techniques that simulate this feature in software, such as PaX [REF-60] [REF-61]. These techniques ensure that any instruction executed is exclusively at a memory address that is part of the code segment. For more information on these techniques see D3-PSEP (Process Segment Execution Prevention) from D3FEND [REF-1336].
  • 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. When accessing a user-controlled array index, use a stringent range of values that are within the target array. Make sure that you do not allow negative values to be used. That is, verify the minimum as well as the maximum of the range of acceptable values.
  • Implementation: Be especially careful to validate all input when invoking code that crosses language boundaries, such as from an interpreted language to native code. This could create an unexpected interaction between the language boundaries. Ensure that you are not violating any of the expectations of the language with which you are interfacing. For example, even though Java may not be susceptible to buffer overflows, providing a large argument in a call to native code might trigger an overflow.
  • Architecture and Design, Operation: Run your code using the lowest privileges that are required to accomplish the necessary tasks [REF-76]. If possible, create isolated accounts with limited privileges that are only used for a single task. That way, a successful attack will not immediately give the attacker access to the rest of the software or its environment. For example, database applications rarely need to run as the database administrator, especially in day-to-day operations.
  • Architecture and Design, Operation: Run the code in a "jail" or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which files can be accessed in a particular directory or which commands can be executed by the software. OS-level examples include the Unix chroot jail, AppArmor, and SELinux. In general, managed code may provide some protection. For example, java.io.FilePermission in the Java SecurityManager allows the software to specify restrictions on file operations. This may not be a feasible solution, and it only limits the impact to the operating system; the rest of the application may still be subject to compromise. Be careful to avoid CWE-243 and other weaknesses related to jails.

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-g274-c6jj-h78p
PocketMine-MP allows malicious client data to waste server resources due to lack of limits for explode()
Medium Also affects pocketmine/pocketmine-mp
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