What’s Vulnerable › Vulnerabilities

CVE-2023-33182: Nextcloud Contacts photos only sanitized if mime type is all lower case

• Severity: medium (CVSS 4.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.8% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2023-05-30 · updated 2026-06-17
• Weakness: CWE-20

Description

Contacts app for Nextcloud easily syncs contacts from various devices with your Nextcloud and allows editing. The unsanitized SVG is converted to a JavaScript blob (in memory data) that the Avatar can't render. Due to this constellation the missing sanitization does not seem to be exploitable. It is recommended that the Contacts app is upgraded to 5.0.3 or 4.2.4

Affected products

• Nextcloud Contacts: from 4.1.0 before 4.2.4; from 5.0.0 before 5.0.3 — fixed in 4.2.4, 5.0.3

How to fix

Upgrade to a fixed version: Nextcloud Contacts 4.2.4, 5.0.3. Check the vendor advisory for mitigations.

References

• https://github.com/nextcloud/contacts/pull/3199
• https://github.com/nextcloud/security-advisories/security/advisories/GHSA-hxr6-cx85-gcjx
• https://hackerone.com/reports/1789602
• https://github.com/nextcloud/contacts/pull/3199
• https://github.com/nextcloud/security-advisories/security/advisories/GHSA-hxr6-cx85-gcjx
• https://hackerone.com/reports/1789602

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