Vulnerability · Published Oct 16, 2023 · Assigned by GitHub_M

CVE-2023-45150Inviting excessive long email addresses to a calendar event makes the Nextcloud server unresponsive

Medium 4.3

In plain English

A medium-severity uncontrolled resource consumption in security-advisories from nextcloud. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 41% of all known vulnerabilities).

Severity (CVSS 3.1)4.3Medium

Exploit odds (30 days)0.5%top 58.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

Nextcloud calendar is a calendar app for the Nextcloud server platform. Due to missing precondition checks the server was trying to validate strings of any length as email addresses even when megabytes of data were provided, eventually making the server busy and unresponsive. It is recommended that the Nextcloud Calendar app is upgraded to 4.4.4. The only workaround for users unable to upgrade is to disable the calendar app.

Affected products (as reported)

Vendor	Product	Versions
nextcloud	security-advisories	>= 1.0.0, < 4.4.4

Weakness: CWE-400 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

References

https://github.com/nextcloud/security-advisories/security/advisories/GHSA-r936-8gwm-w452 x_refsource_CONFIRM
https://github.com/nextcloud/calendar/pull/5358 x_refsource_MISC
https://hackerone.com/reports/2058337 x_refsource_MISC