CVE-2026-33534

Sažetak

EspoCRM is an open source customer relationship management application. Versions 9.3.3 and below have an authenticated Server-Side Request Forgery (SSRF) vulnerability that allows bypassing the internal-host validation logic by using alternative IPv4 representations such as octal notation (e.g., 0177.0.0.1 instead of 127.0.0.1). This is caused by HostCheck::isNotInternalHost() function relying on PHP's filter_var(..., FILTER_VALIDATE_IP), which does not recognize alternative IP formats, causing the validation to fall through to a DNS lookup that returns no records and incorrectly treats the host as safe, however the cURL subsequently normalizes the address and connects to the loopback destination. Through the confirmed /api/v1/Attachment/fromImageUrl endpoint, an authenticated user can force the server to make requests to loopback-only services and store the fetched response as an attachment. This vulnerability is distinct from CVE-2023-46736 (which involved redirect-based SSRF) and may allow access to internal resources reachable from the application runtime. This issue has been fixed in version 9.3.4.

Reference

CVSS

Base:	4.3
Impact:	1.4
Exploitability:	2.8

Pristup

Vektor	Složenost	Autentikacija
NETWORK	LOW	LOW

Impact

Povjerljivost	Cjelovitost	Dostupnost
LOW	NONE	NONE

CVSS vektor

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

Zadnje važnije ažuriranje

17-04-2026 - 15:38

Objavljeno

13-04-2026 - 20:16