Security readout for executives and security teams
Plain-English summary
CVE-2021-47944 is an application crash issue in memono Notepad 4.2 on iOS. The public sources describe a denial-of-service condition triggered by overly large note content. It does not describe data theft, code execution, or system compromise, but it can disrupt users who rely on the app.
Executive priority
Treat this as a targeted mobile app availability risk. Prioritize inventory and update decisions for managed iOS fleets, but do not treat it as confirmed enterprise compromise based on the provided sources.
Technical view
The issue is reported as CWE-789 in memono Notepad 4.2. Excessively large input in note fields can cause the application to crash, producing high availability impact in the affected app. The source bundle lists CVSS 4.0 score 8.7 and references a public ExploitDB entry.
Likely exposure
Exposure appears limited to environments where memono Notepad version 4.2 is installed, especially managed or user-owned iOS devices. The bundle provides no CPEs, deployment prevalence, or server-side exposure evidence.
Exploitation context
A public ExploitDB reference exists, but the bundle does not show CISA KEV listing or confirmed active exploitation. The described outcome is application denial of service, not confirmed device compromise.
Researcher notes
Evidence is narrow: affected product/version, crash impact, CVSS, CWE, and a public exploit reference. Sources do not name a patch, vendor advisory, active exploitation, broader version range, or confidentiality/integrity impact.
Mitigation direction
- Identify managed devices running memono Notepad 4.2.
- Check vendor or App Store guidance for fixed versions.
- Update, remove, or restrict version 4.2 where practical.
- Document business dependence on the app before broad removal.
- Monitor advisories for patch or mitigation updates.
Validation and detection
- Review MDM inventory for memono Notepad installations.
- Confirm installed app versions, prioritizing version 4.2.
- Check whether affected users rely on the app for business workflows.
- Track CVE, VulnCheck, and vendor sources for updates.
- Avoid reproducing crash behavior on production devices.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-789: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-47944 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.7 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
2 official scoresWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N——VulnCheckCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6VulnCheckVulnerability scoring details
Base CVSS 4.0 score
8.7HighVector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- ExploitDB-49977CVE reference, VulnCheck · exploit
- VulnCheck Advisory: memono Notepad 4.2 Denial of Service via Buffer OverflowCVE reference, VulnCheck · third-party-advisory
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Memory Allocation with Excessive Size Value
Memory Allocation with Excessive Size Value represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.