OpenComputers: Server-Side Request Forgery
CVE-2023-37261 is a high-severity server-side request forgery vulnerability in OpenComputers from MightyPirates, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected OpenComputers versions: >= 1.2.0, < 1.8.3. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.79% chance of exploitation within 30 days, higher than 57% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update opencomputers to 1.8.3 or a later version.
- Read the advisory on github.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| MightyPirates | OpenComputers | >= 1.2.0, < 1.8.3 | Not stated |
| Opencomputers | opencomputers | 1.2.0 up to, but not including, 1.8.3 | 1.8.3 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 9.6 | Critical | CNA (github.com) |
| CVSS 3.1 | 8.8 | High | NVD |
Official description
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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Server-Side Request Forgery
The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.
How developers prevent this class of flaw
- If there is a known list of applications, IP, hostname, and/or domains to which the product is allowed to communicate, then use allowlists to ensure that outgoing requests are restricted to these known entities. The allowlists could be in the application code or possibly enforced by firewalls or network segmentation.
- If the product is expected to be able to connect to arbitrary IP addresses or domains, consider using a denylist that includes private network addresses, internal domain names, etc. The denylist could be in the application code or possibly enforced by firewalls or network segmentation.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Patches and release notes
Other references
Other vulnerabilities in OpenComputers
- 7.7 High severity
Recent Server-Side Request Forgery vulnerabilities
- 8.8 High severity
- 9.8 Critical severity
- 7.5 High severity
- 7.5 High severity
- 9.8 Critical severity
- 8.8 High severity
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