CVE Vulnerabilities

CVE-2020-4042

Authentication Bypass by Capture-replay

Published: Jul 10, 2020 | Modified: Jul 15, 2020
CVSS 3.x
6.8
MEDIUM
Source:
NVD
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N
CVSS 2.x
4.3 MEDIUM
AV:N/AC:M/Au:N/C:N/I:P/A:N
RedHat/V2
RedHat/V3
Ubuntu

Bareos before version 19.2.8 and earlier allows a malicious client to communicate with the director without knowledge of the shared secret if the director allows client initiated connection and connects to the client itself. The malicious client can replay the Bareos directors cram-md5 challenge to the director itself leading to the director responding to the replayed challenge. The response obtained is then a valid reply to the directors original challenge. This is fixed in version 19.2.8.

Weakness

A capture-replay flaw exists when the design of the product makes it possible for a malicious user to sniff network traffic and bypass authentication by replaying it to the server in question to the same effect as the original message (or with minor changes).

Affected Software

Name Vendor Start Version End Version
Bareos Bareos * 19.2.7 (including)
Bareos Bareos 19.2.8-pre (including) 19.2.8-pre (including)

Potential Mitigations

References