CVE-2026-33659

EspoCRM is an open source customer relationship management application. In versions 9.3.3 and below, the POST /api/v1/Attachment/fromImageUrl endpoint is vulnerable to Server-Side Request Forgery (SSRF) via a DNS rebinding (TOCTOU) condition. Host validation uses dns_get_record() but the actual HTTP request resolves hostnames through curl's internal resolver (gethostbyname()), allowing the two lookups to return different IP addresses for the same hostname. A secondary issue exists where an empty DNS result (due to DNS failure, IPv6-only domains, or non-existent hostnames) causes the validation to implicitly allow the host without further checks. An authenticated attacker with default attachment creation access can exploit this gap to bypass internal IP restrictions and scan internal network ports, confirm the existence of internal hosts, and interact with internal HTTP-based services, though data extraction from binary protocol services and remote code execution are not possible through this endpoint. This issue has been fixed in version 9.3.4.
Configurations

Configuration 1 (hide)

cpe:2.3:a:espocrm:espocrm:*:*:*:*:*:*:*:*

History

22 Apr 2026, 00:07

Type Values Removed Values Added
References () https://github.com/espocrm/espocrm/commit/dca03cc3458e487362c26c746378a2d4de9990b1 - () https://github.com/espocrm/espocrm/commit/dca03cc3458e487362c26c746378a2d4de9990b1 - Patch
References () https://github.com/espocrm/espocrm/releases/tag/9.3.4 - () https://github.com/espocrm/espocrm/releases/tag/9.3.4 - Release Notes
References () https://github.com/espocrm/espocrm/security/advisories/GHSA-6m4j-fwrx-crh7 - () https://github.com/espocrm/espocrm/security/advisories/GHSA-6m4j-fwrx-crh7 - Exploit, Vendor Advisory
First Time Espocrm espocrm
Espocrm
CPE cpe:2.3:a:espocrm:espocrm:*:*:*:*:*:*:*:*

14 Apr 2026, 15:16

Type Values Removed Values Added
References () https://github.com/espocrm/espocrm/security/advisories/GHSA-6m4j-fwrx-crh7 - () https://github.com/espocrm/espocrm/security/advisories/GHSA-6m4j-fwrx-crh7 -

13 Apr 2026, 21:16

Type Values Removed Values Added
New CVE

Information

Published : 2026-04-13 21:16

Updated : 2026-04-22 00:07


NVD link : CVE-2026-33659

Mitre link : CVE-2026-33659

CVE.ORG link : CVE-2026-33659


JSON object : View

Products Affected

espocrm

  • espocrm
CWE
CWE-367

Time-of-check Time-of-use (TOCTOU) Race Condition

CWE-918

Server-Side Request Forgery (SSRF)