CVE-2023-49790

Physical file access via unlimited PIN guesses

Published Dec 22, 2023 · Updated Aug 2, 2024

Improper authentication in Nextcloud Files for iOS 4.9.1 and earlier allows physically proximate attackers to bypass the four-digit app PIN. The PIN entry flow permits unlimited consecutive guesses because failed attempts impose no persistent lockout; the patch adds escalating delays after three failures. Access requires possession of an unlocked iOS device with the app PIN enabled, and a successful guess exposes the signed-in user's files and app functions.

CVSS severity4.3
Medium
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper authentication in Nextcloud Files for iOS 4.9.1 and earlier allows physically proximate attackers to bypass the four-digit app PIN. The PIN entry flow permits unlimited consecutive guesses because failed attempts impose no persistent lockout; the patch adds escalating delays after three failures. Access requires possession of an unlocked iOS device with the app PIN enabled, and a successful guess exposes the signed-in user's files and app functions.

The record

CVE
CVE-2023-49790
Published
Dec 22, 2023
Updated
Aug 2, 2024
Vendor
Nextcloud GmbH
Product
Security Advisories
Classifications
CWE-287, T1409
Attack vector
physical
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 22, 2023CVE publishedPublication date reported by the CVE source.
  2. Aug 2, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 4.9.2

What conditions does exploitation require?

Attack vectorphysical
Required privilegesunauthenticated

What is affected?

Nextcloud GmbH · Security Advisoriesversion=< 4.9.2

Published CVSS scores

4.3GitHub, Inc.CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorphysical
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-287Improper Authentication
T1409Access Stored Application Data

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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