Attacker Value
Unknown
(0 users assessed)
Exploitability
Unknown
(0 users assessed)
User Interaction
None
Privileges Required
None
Attack Vector
Network
0

CVE-2021-29475

Disclosure Date: April 26, 2021
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Description

HedgeDoc (formerly known as CodiMD) is an open-source collaborative markdown editor. An attacker is able to receive arbitrary files from the file system when exporting a note to PDF. Since the code injection has to take place as note content, there fore this exploit requires the attackers ability to modify a note. This will affect all instances, which have pdf export enabled. This issue has been fixed by https://github.com/hedgedoc/hedgedoc/commit/c1789474020a6d668d616464cb2da5e90e123f65 and is available in version 1.5.0. Starting the CodiMD/HedgeDoc instance with CMD_ALLOW_PDF_EXPORT=false or set "allowPDFExport": false in config.json can mitigate this issue for those who cannot upgrade. This exploit works because while PhantomJS doesn’t actually render the file:/// references to the PDF file itself, it still uses them internally, and exfiltration is possible, and easy through JavaScript rendering. The impact is pretty bad, as the attacker is able to read the CodiMD/HedgeDoc config.json file as well any other files on the filesystem. Even though the suggested Docker deploy option doesn’t have many interesting files itself, the config.json still often contains sensitive information, database credentials, and maybe OAuth secrets among other things.

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CVSS V3 Severity and Metrics
Base Score:
10.0 Critical
Impact Score:
5.8
Exploitability Score:
3.9
Vector:
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N
Attack Vector (AV):
Network
Attack Complexity (AC):
Low
Privileges Required (PR):
None
User Interaction (UI):
None
Scope (S):
Changed
Confidentiality (C):
High
Integrity (I):
High
Availability (A):
None

General Information

Vendors

  • hedgedoc

Products

  • hedgedoc

Additional Info

Technical Analysis