CVE-2020-1766: XSS in OTRS Support System
Platform
otrs
Component
otrs
Fixed in
5.0.1
6.0.1
7.0.1
CVE-2020-1766 describes a cross-site scripting (XSS) vulnerability affecting OTRS, a popular open-source support ticket system. This vulnerability arises from improper handling of uploaded images, allowing an attacker to potentially execute malicious JavaScript within an agent's browser. The vulnerability impacts OTRS Community Edition 5.0.x versions prior to 5.0.39, 6.0.x versions prior to 6.0.24, and 7.0.x versions prior to 7.0.14. A fix is available in version 7.0.14.
Impact and Attack Scenarios
An attacker could exploit this vulnerability by crafting a malicious SVG file disguised as a JPG image. When an OTRS agent attempts to view or process this file, the system incorrectly renders it as an inline JPG, triggering the embedded JavaScript code. This could lead to various malicious actions, including session hijacking, redirection to phishing sites, or defacement of the OTRS interface. The impact is primarily limited to the agent's browser session, but a successful attack could compromise sensitive information or allow the attacker to impersonate the agent within the OTRS system. The low CVSS score reflects the difficulty of exploitation and limited scope of impact.
Exploitation Context
CVE-2020-1766 was publicly disclosed on January 10, 2020. There is no evidence of active exploitation campaigns targeting this vulnerability. No public proof-of-concept (PoC) code has been widely released. The vulnerability is not listed on the CISA KEV catalog. The low CVSS score suggests a relatively low probability of exploitation in the wild.
Threat Intelligence
Exploit Status
EPSS
0.77% (73% percentile)
CVSS Vector
What do these metrics mean?
- Attack Vector
- Network — remotely exploitable over the internet. No physical or local access required. Widest attack surface.
- Attack Complexity
- High — requires a race condition, non-default configuration, or specific circumstances. Harder to exploit reliably.
- Privileges Required
- High — admin or privileged account required to exploit.
- User Interaction
- Required — victim must take an action: open a file, click a link, or visit a crafted page.
- Scope
- Unchanged — impact is limited to the vulnerable component itself.
- Confidentiality
- None — no confidentiality impact. Attacker cannot read protected data.
- Integrity
- Low — attacker can modify some data with limited scope or impact.
- Availability
- None — no availability impact. Service remains fully operational.
Affected Software
Weakness Classification (CWE)
Timeline
- Reserved
- Published
- Modified
- EPSS updated
Mitigation and Workarounds
The primary mitigation for CVE-2020-1766 is to upgrade OTRS to version 7.0.14 or later. If an immediate upgrade is not feasible, consider implementing strict input validation on uploaded files to prevent the processing of SVG files when JPGs are expected. Web Application Firewalls (WAFs) configured to detect and block malicious JavaScript payloads can also provide a layer of defense. Regularly review OTRS configurations and ensure that image processing settings are secure. After upgrading, confirm the fix by attempting to upload a test SVG file and verifying that it is handled correctly and does not trigger JavaScript execution.
How to fix
Update OTRS to the latest available version. Versions 5.0.40, 6.0.25, and 7.0.14 address this vulnerability. See the release notes for more details about the update.
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Frequently asked questions
What is CVE-2020-1766 — XSS in OTRS Support System?
CVE-2020-1766 is a cross-site scripting (XSS) vulnerability in OTRS versions prior to 7.0.14. It allows an attacker to execute malicious JavaScript by exploiting improper handling of uploaded SVG files.
Am I affected by CVE-2020-1766 in OTRS Support System?
You are affected if you are running OTRS Community Edition 5.0.x versions prior to 5.0.39, 6.0.x versions prior to 6.0.24, or 7.0.x versions prior to 7.0.14.
How do I fix CVE-2020-1766 in OTRS Support System?
Upgrade OTRS to version 7.0.14 or later. Implement strict input validation on uploaded files as an interim measure.
Is CVE-2020-1766 being actively exploited?
There is no evidence of active exploitation campaigns targeting CVE-2020-1766 at this time.
Where can I find the official OTRS advisory for CVE-2020-1766?
Refer to the official OTRS security advisory: https://otrs.com/security-advisories/otrs-security-advisory-cve-2020-1766/
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