Multiple vulnerabilities in HedgeDoc

Published: 2021-01-04

Risk	High
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2020-26287 CVE-2020-26286
CWE-ID	CWE-79 CWE-434
Exploitation vector	Network
Public exploit	N/A
Vulnerable software Subscribe	HedgeDoc Client/Desktop applications / Other client software
Vendor	HedgeDoc

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Stored cross-site scripting

EUVDB-ID: #VU49233

Risk: Low

CVSSv3.1: 6.3 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-26287

CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Exploit availability: No

Description

The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.

The vulnerability exists due to insufficient sanitization of user-supplied data within mermaid diagrams. A remote attacker can inject and execute arbitrary HTML and script code in user's browser in context of vulnerable website.

Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

HedgeDoc: 0.3.3 - 1.7.0

External links

http://github.com/Alemmi/ctf-writeups/blob/main/hxpctf-2020/hackme/solution.md
http://github.com/hackmdio/codimd/issues/1630
http://github.com/hedgedoc/hedgedoc/commit/58276ebbf4504a682454a3686dcaff88bc1069d4
http://github.com/hedgedoc/hedgedoc/releases/tag/1.7.1
http://github.com/hedgedoc/hedgedoc/security/advisories/GHSA-g6w6-7xf9-m95p

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

2) Arbitrary file upload

EUVDB-ID: #VU49234

Risk: High

CVSSv3.1: 8.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-26286

CWE-ID: CWE-434 - Unrestricted Upload of File with Dangerous Type