Lucene search

GoogleOSV:GO-2022-0370

HistoryJul 29, 2022 - 8:00 p.m.

Man-in-the-middle attack due to improper validation of certificate in mellium.im/xmpp

2022-07-2920:00:14

Google

osv.dev

man-in-the-middle

certificate validation

dns spoofing

wss endpoint

tls certificate

dns record

attacker

servername field

software

CVSS2

4.3

Attack Vector

NETWORK

Attack Complexity

MEDIUM

Authentication

NONE

Confidentiality Impact

NONE

Integrity Impact

PARTIAL

Availability Impact

NONE

AV:N/AC:M/Au:N/C:N/I:P/A:N

CVSS3

5.9

Attack Vector

NETWORK

Attack Complexity

HIGH

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

NONE

Integrity Impact

HIGH

Availability Impact

NONE

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N

AI Score

5.2

Confidence

High

EPSS

0.001

Percentile

34.3%

JSON

Websocket client connections are vulnerable to man-in-the-middle attacks via DNS spoofing.

When looking up a WSS endpoint using a DNS TXT record, the server TLS certificate is incorrectly validated using the name of the server returned by the TXT record request, not the name of the the server being connected to. This permits any attacker that can spoof a DNS record to redirect the user to a server of their choosing.

Providing a *tls.Config with a ServerName field set to the correct destination hostname will avoid this issue.