# Incorrect Handling of Non-Boolean Comparisons During Minification in uglify-js

Advisory record · `GHSA-34r7-q49f-h37c`

- **Identifiers:** `GHSA-34r7-q49f-h37c` · `CVE-2015-8857`
- **State:** Confirmed
- **Severity:** CVSS 9.8 Critical
- **Critical:** Yes: CVSS 9+
- **Weakness (CWE):** [CWE-670](https://cwe.mitre.org/data/definitions/670.html) · [CWE-1254](https://cwe.mitre.org/data/definitions/1254.html)
- **Tags:** [CWE-670](https://agentprime.io/advisories/tag/cwe-670.md) · [CWE-1254](https://agentprime.io/advisories/tag/cwe-1254.md)
- **Published:** 24 Oct 2017
- **Updated:** 16 Feb 2024
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 24 Oct 2017, 18:33 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Critical

Critical, because:

- CVSS score 9.8: 9.0 or more.

How we decide what’s critical: <https://agentprime.io/advisories/critical.md>

## Affected packages

- `uglify-js` (npm): affected `<2.4.24`; fixed in `2.4.24`
- `uglifier` (RubyGems): affected `<2.7.2`; fixed in `2.7.2`

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 9.8 Critical, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`, from GitHub Advisory Database

- **CISA KEV:** Not listed.
- **EPSS:** 0.036, the 89th percentile, on 8 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

This record came from the full history of the GitHub Advisory Database, published 24 Oct 2017. New records show when each source confirmed them.

## Sources

- [GitHub Advisory Database: GHSA-34r7-q49f-h37c](https://github.com/advisories/GHSA-34r7-q49f-h37c)
- [OSV: GHSA-34r7-q49f-h37c](https://osv.dev/vulnerability/GHSA-34r7-q49f-h37c)
- <https://nvd.nist.gov/vuln/detail/CVE-2015-8857>
- <https://github.com/mishoo/UglifyJS2/issues/751>
- <https://github.com/lautis/uglifier/commit/4677bfe38142937ff952f95605bcec4618892c3e>
- <https://github.com/mishoo/UglifyJS2>
- <https://github.com/rubysec/ruby-advisory-db/blob/master/gems/uglifier/CVE-2015-8857.yml>
- <https://web.archive.org/web/20200227190830/http://www.securityfocus.com/bid/96410>
- <https://zyan.scripts.mit.edu/blog/backdooring-js>
- <http://www.openwall.com/lists/oss-security/2016/04/20/11>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-34r7-q49f-h37c>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-34r7-q49f-h37c/>. Everything for agents: <https://agentprime.io/llms.txt>.