GHSA-m5w8-4gq2-6f8x: vm2: NodeVM `builtin: ['*']` exposes `os` and `dns` — process-wide observability reads AND writes that hijack the host (sibling class of GHSA-9g8x-92q2-p28f)

Should you act?

• Only if you depend on one of the packages below, directly or transitively, in a vulnerable version. Check your lockfile with npm audit (or: npm ls <package>).
• No CVE has been assigned, so it will not appear in CVE-based scanners that ignore GitHub advisories. npm audit, pip-audit and Dependabot do read GitHub advisories.

Affected packages

Details

NodeVM builtin: [''] exposes os and dns — process-wide observability reads AND writes that hijack the host (sibling class of GHSA-9g8x-92q2-p28f)

CWE: CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor) chained with CWE-732 (Incorrect Permission Assignment for Critical Resource) and CWE-285 (Improper Authorization) — same class the maintainer codified as Defense Invariant #13 in lib/builtin.js and as Category 35 / GHSA-9g8x in docs/ATTACKS.md.

CVSS v3.1: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L → 9.3 (Critical)

(Scope = Changed because the data being read and the state being written both belong to the host process, not the sandbox. Confidentiality = High because os.userInfo() returns host UID/GID/username/homedir + os.networkInterfaces() returns the full host network topology including container/VM interfaces with IPs and MAC addresses. Integrity = High because dns.setServers() is a process-wide write that hijacks every subsequent DNS lookup the host makes — including outbound HTTP, telemetry, npm/registry, and any host code that uses fetch or URL-based fs paths. Privileges Required = None because the attacker controls sandbox code, which is the threat model NodeVM exists to mitigate.)

Summary

GHSA-9g8x-92q2-p28f closed the "process-wide observability builtins" class by adding diagnosticschannel, asynchooks, perfhooks, and v8 to DANGEROUSBUILTINS in lib/builtin.js. The fix's rationale (in the commit message and docs/ATTACKS.md Category 35) is general:

> Process-wide observability builtins. Unlike most Node builtins, these expose state of the entire host process rather than sandbox-local state — the vm2 boundary cannot usefully contain them because the data they surface […] belongs to the embedder. Even a readonly proxy that forwards every call to the host module is a working host-data exfiltration primitive.

Two builtins satisfying the same description were not added: os and dns. Both are reachable today under the documented builtin: [''] configuration; both expose host-process state that the vm.readonly() proxy cannot localise; and both have write APIs that mutate global host-process state from the sandbox (os.setPriority(), dns.setServers(), dns.setDefaultResultOrder()). dns.setServers() in particular turns sandbox code into a process-wide DNS…

CVSS: 10.0 (v3.1) CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L

Sources and references

1. GitHub Advisory GHSA-m5w8-4gq2-6f8x github.com
2. github.com github.com
3. github.com github.com

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