CVE-2021-3716 Information

Description

A flaw was found in nbdkit due to to improperly caching plaintext state across the STARTTLS encryption boundary. A MitM attacker could use this flaw to inject a plaintext NBD_OPT_STRUCTURED_REPLY before proxying everything else a client sends to the server potentially leading the client to terminate the NBD session. The highest threat from this vulnerability is to system availability.

CVSS Vector

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

Reference

https://www.openwall.com/lists/oss-security/2021/08/18/2 https://gitlab.com/nbdkit/nbdkit/-/commit/09a13dafb7bb3a38ab52eb5501cba786365ba7fd https://gitlab.com/nbdkit/nbdkit/-/commit/6c5faac6a37077cf2366388a80862bb00616d0d8 https://listman.redhat.com/archives/libguestfs/2021-August/msg00083.html https://bugzilla.redhat.com/show_bug.cgi?id=1994695

Attack Complexity

HIGH

Privileges Required

LOW

User Interaction Required

LOW

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

NONE

Availability Impact

NONE

Base Score

LOW

Base Severity

3.1