# CVE-2021-47944: memono Notepad denial of service via excessive character input

Source: https://junglewise.ai/threats/cve-2021-47944-memono-notepad-denial-of-service-via-excessive-character-input  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-10. Updated: 2026-07-24  
License: CC BY 4.0 with a link back

CVE-2021-47944 · Severity: high · CVSS 7.5 · Published 2026-05-10

memono Notepad is a note-taking application for iOS devices. A vulnerability in version 4.2 allows the application to be crashed by pasting an extremely large amount of text into a note field. This results in a denial of service, making the application unusable until it is restarted or the problematic data is removed.

## Quick answers

**Is CVE-2021-47944 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2021-47944 being exploited in the wild.

**How severe is CVE-2021-47944?** High severity, with a CVSS score of 7.5, published 10 May 2026.

**Which products and versions are affected?** memono Notepad 4.2.

**Is there a fix for CVE-2021-47944?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2021-47944 attacked?** It is attacked with local access, in a network appliance.

**Am I affected by CVE-2021-47944?** Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A denial of service vulnerability exists in memono Notepad 4.2 for iOS due to improper handling of large memory allocations (CWE-789). The application fails to adequately validate the length of input when text is pasted into a note field. An attacker can trigger an application crash by pasting a buffer of approximately 700,000 characters (e.g., two instances of a 350,000-character string) into a new note. This local exploit was verified on iOS 14.2. While some sources list a network attack vector, the primary exploitation method requires local user interaction to paste the malicious payload.

## Affected products

- memono Notepad 4.2

## Timeline

- 2021-06-09: disclosed: Initial discovery and PoC by Geovanni Ruiz
- 2026-05-10: advisory: NVD/VulnCheck advisory published

## References

- [https://www.exploit-db.com/exploits/49977](https://www.exploit-db.com/exploits/49977)
- [https://www.vulncheck.com/advisories/memono-notepad-denial-of-service-via-buffer-overflow](https://www.vulncheck.com/advisories/memono-notepad-denial-of-service-via-buffer-overflow)