CVE-2023-37261 in OpenComputers
Summary
by MITRE • 07/08/2023
OpenComputers is a Minecraft mod that adds programmable computers and robots to the game. This issue affects every version of OpenComputers with the Internet Card feature enabled; that is, OpenComputers 1.2.0 until 1.8.3 in their most common, default configurations. If the OpenComputers mod is installed as part of a Minecraft server hosted on a popular cloud hosting provider, such as AWS, GCP and Azure, those metadata services' API endpoints are not forbidden (aka "blacklisted") by default. As such, any player can gain access to sensitive information exposed via those metadata servers, potentially allowing them to pivot or privilege escalate into the hosting provider. In addition, IPv6 addresses are not correctly filtered at all, allowing broader access into the local IPv6 network. This can allow a player on a server using an OpenComputers computer to access parts of the private IPv4 address space, as well as the whole IPv6 address space, in order to retrieve sensitive information.
OpenComputers v1.8.3 for Minecraft 1.7.10 and 1.12.2 contains a patch for this issue. Some workarounds are also available. One may disable the Internet Card feature completely. If using OpenComputers 1.3.0 or above, using the allow list (`opencomputers.internet.whitelist` option) will prohibit connections to any IP addresses and/or domains not listed; or one may add entries to the block list (`opencomputers.internet.blacklist` option). More information about mitigations is available in the GitHub Security Advisory.
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Analysis
by VulDB Data Team • 07/25/2023
The vulnerability described in CVE-2023-37261 represents a critical network exposure issue within the OpenComputers Minecraft mod that enables unauthorized access to cloud infrastructure metadata services and internal network resources. This security flaw affects versions 1.2.0 through 1.8.3 of the mod when the Internet Card feature is enabled, creating a significant attack surface that can be exploited by malicious players within Minecraft servers. The vulnerability specifically targets cloud hosting environments where popular providers such as AWS, Google Cloud Platform, and Microsoft Azure expose metadata services that contain sensitive information about the underlying infrastructure, including instance identifiers, security credentials, and network configurations.
The technical implementation of this vulnerability stems from inadequate network filtering and access control mechanisms within the mod's Internet Card functionality. The flaw allows players to make network requests to cloud metadata endpoints that should normally be restricted to the local infrastructure, creating a path for information disclosure attacks. This issue is particularly concerning because it leverages the default configurations of popular cloud hosting providers where metadata services are accessible via specific API endpoints that are not blacklisted by default within the mod's network restrictions. The vulnerability also includes a secondary issue where IPv6 addresses are not properly filtered, extending the attack surface to encompass the entire IPv6 address space and potentially allowing access to private IPv4 networks as well.
The operational impact of this vulnerability extends beyond simple information disclosure, as it creates opportunities for privilege escalation and lateral movement within cloud environments. Attackers can potentially extract sensitive credentials, instance metadata, and network configuration details that could be used to pivot into the hosting provider's infrastructure or escalate their privileges within the cloud environment. The vulnerability affects Minecraft servers hosted on cloud infrastructure, making it particularly dangerous in shared hosting environments where multiple users might be accessing the same underlying cloud resources. This creates a vector for attackers to gain insights into the hosting provider's infrastructure that could be used for further exploitation or to map out network topologies for more sophisticated attacks.
The vulnerability aligns with several cybersecurity standards and frameworks, particularly CWE-284 which addresses improper access control, and CWE-312 which covers exposure of sensitive information through data leakage. From an ATT&CK framework perspective, this vulnerability maps to T1082 (System Information Discovery) and T1566 (Phishing) as it enables information gathering and potential credential theft. The issue also relates to T1046 (Network Service Scanning) and T1592 (Get Access) as it allows attackers to enumerate network services and potentially gain unauthorized access to cloud resources. The mod's default configuration failure to implement proper network filtering creates a persistent security weakness that can be exploited by any player with access to the Internet Card functionality.
Mitigation strategies for this vulnerability include several approaches that address the root cause of the network access control failures. The most effective solution involves disabling the Internet Card feature entirely if it is not required for server operations, which removes the attack surface completely. For administrators who need to maintain the Internet Card functionality, the mod provides specific configuration options including the use of allow lists through the `opencomputers.internet.whitelist` parameter and blacklisting through the `opencomputers.internet.blacklist` option. These configuration parameters provide granular control over network access and can effectively restrict connections to only trusted IP addresses and domains. The patch included in OpenComputers v1.8.3 for Minecraft 1.7.10 and 1.12.2 addresses the core filtering issues and should be implemented immediately by administrators running affected versions of the mod. Additionally, server administrators should implement network-level firewalls and access control lists to further restrict outbound connections from Minecraft servers to prevent potential exploitation even if the mod's built-in protections fail.