GHSA-4g2x-vq5p-5vj6
Budibase affected by VM2 Constructor Escape Vulnerability
- Severity
- 9.8 / 10
- Critical · CVSS 3.1
- Exploit chance (EPSS)
- —
- No score published
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-94 Improper Control of Generation of Code ('Code Injection')
- Fix
2.20.0- Upgrade @budibase/server to this version or later
Description
Impact
Previously, budibase used a library called vm2 for code execution inside the Budibase builder and apps, such as the UI below for configuring bindings in the design section.
Screenshot 2024-03-01 at 13 50 16
Due to a vulnerability in vm2, any environment that executed the code server side (automations and column formulas) was susceptible to this vulnerability, allowing users to escape the sandbox provided by vm2, and to expose server side variables such as process.env. It's recommended by the authors of vm2 themselves that you should move to another solution for remote JS execution due to this vulnerability.
Patches
We moved our entire JS sandbox infrastructure over to isolated-vm, a much more secure and recommended library for remote code execution in 2.20.0. This also comes with a performance benefit in the way we cache and execute your JS server side. The budibase cloud platform has been patched already and is not running vm2, but self host users will need to manage the updates by themselves.
If you are a self hosted user, you can take the following steps to reproduce the exploit and to verify if your installation is currently affected.
Create a new formula column on one of your tables in the data section with the following configuration. Screenshot 2024-03-01 at 14 04 28
Add the following JS function to the formula and save. Screenshot 2024-03-01 at 14 05 19
If your installation is vulnerable, when the formula evaluates you will be able to see the printed process.env in your new formula field. If not, your installation is not affected.
Workarounds
There is no workaround at this time for any budibase app that uses JS. You must fully migrate post version 2.20.0 to patch the vulnerability.
References
Affected versions
npm
| Package | Vulnerable | Fixed in |
|---|---|---|
| @budibase/server | < 2.20.0 |
2.20.0 |
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.
@budibase/server npm → 2.20.0
- npm
npm install @budibase/server@2.20.0- yarn
yarn add @budibase/server@2.20.0- pnpm
pnpm add @budibase/server@2.20.0
Severity breakdown
CVSS 3.1 9.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Weakness
CWE-94: Improper Control of Generation of Code ('Code Injection')
The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.
How to prevent it
- Architecture and Design: Refactor your program so that you do not have to dynamically generate code.
- Architecture and Design: Run your code in a "jail" or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which code can be executed by your product. Examples include the Unix chroot jail and AppArmor. In general, managed code may provide some protection. This may not be a feasible solution, and it only limits the impact to the operating system; the rest of your application may still be subject to compromise. Be careful to avoid CWE-243 and other weaknesses related to jails.
- 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. To reduce the likelihood of code injection, use stringent allowlists that limit which constructs are allowed. If you are dynamically constructing code that invokes a function, then verifying that the input is alphanumeric might be insufficient. An attacker might still be able to reference a dangerous function that you did not intend to allow, such as system(), exec(), or exit().
- Testing: Use dynamic tools and techniques that interact with the product using large test suites with many diverse inputs, such as fuzz testing (fuzzing), robustness testing, and fault injection. The product's operation may slow down, but it should not become unstable, crash, or generate incorrect results.
- Operation: Run the code in an environment that performs automatic taint propagation and prevents any command execution that uses tainted variables, such as Perl's "-T" switch. This will force the program to perform validation steps that remove the taint, although you must be careful to correctly validate your inputs so that you do not accidentally mark dangerous inputs as untainted (see CWE-183 and CWE-184).
- Operation: Run the code in an environment that performs automatic taint propagation and prevents any command execution that uses tainted variables, such as Perl's "-T" switch. This will force the program to perform validation steps that remove the taint, although you must be careful to correctly validate your inputs so that you do not accidentally mark dangerous inputs as untainted (see CWE-183 and CWE-184).
- Implementation: For Python programs, it is frequently encouraged to use the ast.literal_eval() function instead of eval, since it is intentionally designed to avoid executing code. However, an adversary could still cause excessive memory or stack consumption via deeply nested structures [REF-1372], so the python documentation discourages use of ast.literal_eval() on untrusted data [REF-1373].
References
Packages
Other links
Timeline
- Published
- Last updated by the source
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-6x9p-4r67-5gjx Budibase authenticated arbitrary S3 signed upload URL issuance via `/api/attachments/:datasourceId/url` | High | Also affects @budibase/server |
| GHSA-5fpj-28rv-84r7 Budibase: SSRF in Automation Steps - Webhook, Zapier, N8N, Slack, Discord Bypass IP Blacklist | High | Also affects @budibase/server |
| GHSA-hfhx-w8p8-4hc7 Budibase: SSRF via bare fetch() in uploadUrl during AI table generation | Medium | Also affects @budibase/server |
| GHSA-v42f-v8xc-j435 Budibase: SSRF via DNS rebinding in the REST datasource integration | High | Also affects @budibase/server |
| GHSA-pmpg-2mxq-6xwr Budibase: NoSQL injection in MongoDB integration: collection dump, $where JS exec, cross-collection pivot, arbitrary update/delete | High | Also affects @budibase/server |
| GHSA-cr7p-cr3q-h5cm Budibase: Account Enumeration via Login Lockout Response Differential | Medium | Also affects @budibase/server |
| GHSA-pvcr-8mvp-w8qr Budibase: Chat-Link Handoff Identity Confusion (Same-Tenant Account-Link CSRF) | High | Also affects @budibase/server |
| GHSA-2xgg-r2wc-c5r2 Budibase: MySQL DESCRIBE Backtick Injection via multipleStatements in Database Connector | High | Also affects @budibase/server |
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