vulnerability / NVI-00013272 / Revision 1
adm-zip extraction preserves SUID/SGID bits from untrusted ZIPs -> local privilege escalation
GitHub lists this reviewed advisory for adm-zip. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
7.1 high
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
adm-zip
source listed<= 0.6.0
## Summary adm-zip applies the Unix permission bits stored in a zip entry directly to the extracted file via `fs.chmodSync()` when `keepOriginalPermission=true` is passed to `extractAllTo()`/`extractEntryTo()` — and it never filters the setuid/setgid/sticky bits out of those bits. A zip crafted by an attacker can therefore produce an extracted binary with mode `04755`. When extraction runs as root (the default posture in Docker builds, CI runners, and privileged install steps — the exact environments where this flag is used), the resulting root-owned setuid file is executed later by a lesser-privileged user, turning the attacker's code into a root execution. ## Details The mode a zip entry wants is read back from the external file attributes in the header, and the mask used keeps every special bit: ```js // headers/entryHeader.js:187 get fileAttr() { return (_attr || 0) >> 16 & 0xfff; } ``` `0xfff` is `0o7777` — it preserves setuid (`0o4000`), setgid (`0o2000`) and the sticky bit (`0o1000`) along with the rwx bits. Shifting by 16 is the standard Unix convention for where zip stores the mode; the mask is the problem. When the flag is on, that value goes straight to the wri
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
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- GHSA-j5f4-cc29-5x44 ↗
GitHub Advisory Database · vendor advisory
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Public revision history
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- Revision 1 ·
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