ONLYOFFICE all versions as of 2021-11-08 is vulnerable to Improper Input Validation. A lack of input validation can allow an attacker to spoof the names of users who interact with a document, if the document id is known.

ONLYOFFICE all versions as of 2021-11-08 is affected by Incorrect Access Control. An authentication bypass in the document editor allows attackers to edit documents without authentication.

ONLYOFFICE all versions as of 2021-11-08 is vulnerable to Cross Site Scripting (XSS). The "macros" feature of the document editor allows malicious cross site scripting payloads to be used.

ONLYOFFICE all versions as of 2021-11-08 is affected by Incorrect Access Control. An attacker can authenticate with the web socket service of the ONLYOFFICE document editor which is protected by JWT auth by using a default JWT signing key.

ONLYOFFICE all versions as of 2021-11-08 is affected by Incorrect Access Control. Signed document download URLs can be forged due to a weak default URL signing key.

Onlyoffice Document Server v6.0.0 and below and Core 6.1.0.26 and below were discovered to contain a heap overflow via the component DesktopEditor/fontengine/fontconverter/FontFileBase.h.

Onlyoffice Document Server v6.0.0 and below and Core 6.1.0.26 and below were discovered to contain a stack overflow via the component DesktopEditor/common/File.cpp.

A cross-site scripting (XSS) vulnerability in ONLYOFFICE Document Server Example before v7.0.0 allows remote attackers inject arbitrary HTML or JavaScript through /example/editor.

The Translate plugin 6.1.x through 6.3.x before 6.3.0.72 for ONLYOFFICE Document Server lacks escape calls for the msg.data and text fields.

A file extension handling issue was found in [core] module of ONLYOFFICE DocumentServer v4.0.0-9-v5.6.3. An attacker must request the conversion of the crafted file from PPTT into PPTX format. Using the chain of two other bugs related to improper string handling, a remote attacker can obtain remote code execution on DocumentServer.