CVE-2022-21649

Stored XSS via attribute in convos

Convos is an open source multi-user chat that runs in a web browser. Characters starting with "https://" in the chat window create an <a> tag. Stored XSS vulnerability using onfocus and autofocus occurs because escaping exists for "<" or ">" but escaping for double quotes does not exist. Through this vulnerability, an attacker is capable to execute malicious scripts. Users are advised to update as soon as possible.

Affected

convos-chat · convos

CVSS v3.1 NVD

5.4 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

CVSS v3.1 GITHUB

7.6 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N

CVSS v2.0 NVD

3.5 LOWAV:N/AC:M/Au:S/C:N/I:P/A:N

EPSS

0.93% chance of exploitation in the next 30 days, 60th percentile

Published

2022-01-04

Updated

2025-04-22

Proof-of-concept exploits (1)

• https://www.huntr.dev/bounties/4532a0ac-4e7c-4fcf-9fe3-630e132325c0/

Security advisories

• https://blog.pocas.kr/2021/12/30/2021-12-30-s-xss-convos-chat/#Second-vulnerability
• convos-chat/convos/commit/86b2193de375005ba71d9dd53843562c6ac1847c
• convos-chat/convos/security/advisories/GHSA-xmpj-xwm3-vww7
• https://www.huntr.dev/bounties/4532a0ac-4e7c-4fcf-9fe3-630e132325c0

References

• CVE Record
• NVD entry