CVE-2018-1000842

Vulnerability

FatFreeCRM versions <=0.14.1, >=0.15.0 <=0.15.1, >=0.16.0 <=0.16.3, >=0.17.0 <=0.17.2, and ==0.18.0 contain a Cross-Site Scripting (XSS) vulnerability in the app/helpers/tag_helper.rb file, introduced in commit 6d60bc8ed010c4eda05d6645c64849f415f68d65 [1][3]. The vulnerability allows JavaScript payloads embedded in tags used to categorize content to bypass HTML escaping, leading to script execution [3].

Exploitation

An attacker can exploit this vulnerability by creating or modifying content within FatFreeCRM that includes a malicious JavaScript payload in tags. When other users browse to pages displaying that content, the payload executes in their browsers, requiring no special network position or authentication other than being a user who can view the affected content [1][3].

Impact

Successful exploitation enables arbitrary JavaScript execution in the victim's browser, potentially leading to session hijacking, cookie theft, defacement, or unauthorized actions on behalf of the victim within the application [3]. The attack is stored, meaning the payload persists until removed.

Mitigation

The issue is fixed in versions 0.18.1, 0.17.3, 0.16.4, 0.15.2, and 0.14.2 [1][3]. Users should upgrade to the latest patched version. For manual patching, the commit 6d60bc8ed010c4eda05d6645c64849f415f68d65 can be applied [3]. No workarounds are mentioned; upgrading is strongly recommended [3].