Attacker Value
Unknown
(0 users assessed)
Exploitability
Unknown
(0 users assessed)
User Interaction
None
Privileges Required
Low
Attack Vector
Network
0

CVE-2024-47659

Disclosure Date: October 09, 2024 •
CVE-2024-47659 CVSS v3 Base Score: 8.8
Add MITRE ATT&CK tactics and techniques that apply to this CVE.

Description

In the Linux kernel, the following vulnerability has been resolved:

smack: tcp: ipv4, fix incorrect labeling

Currently, Smack mirrors the label of incoming tcp/ipv4 connections:
when a label ‘foo’ connects to a label ‘bar’ with tcp/ipv4,
‘foo’ always gets ‘foo’ in returned ipv4 packets. So,

  1. returned packets are incorrectly labeled (‘foo’ instead of ‘bar’)
  2. ‘bar’ can write to ‘foo’ without being authorized to write.

Here is a scenario how to see this:

  • Take two machines, let’s call them C and S,
    with active Smack in the default state
    (no settings, no rules, no labeled hosts, only builtin labels)

  • At S, add Smack rule ‘foo bar w’
    (labels ‘foo’ and ‘bar’ are instantiated at S at this moment)

  • At S, at label ‘bar’, launch a program
    that listens for incoming tcp/ipv4 connections

  • From C, at label ‘foo’, connect to the listener at S.
    (label ‘foo’ is instantiated at C at this moment)
    Connection succeedes and works.

  • Send some data in both directions.

  • Collect network traffic of this connection.

All packets in both directions are labeled with the CIPSO
of the label ‘foo’. Hence, label ‘bar’ writes to ‘foo’ without
being authorized, and even without ever being known at C.

If anybody cares: exactly the same happens with DCCP.

This behavior 1st manifested in release 2.6.29.4 (see Fixes below)
and it looks unintentional. At least, no explanation was provided.

I changed returned packes label into the ‘bar’,
to bring it into line with the Smack documentation claims.

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CVSS V3 Severity and Metrics
Base Score:
8.8 High
Impact Score:
5.9
Exploitability Score:
2.8
Vector:
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack Vector (AV):
Network
Attack Complexity (AC):
Low
Privileges Required (PR):
Low
User Interaction (UI):
None
Scope (S):
Unchanged
Confidentiality (C):
High
Integrity (I):
High
Availability (A):
High

General Information

Offensive Application
Unknown
Utility Class
Unknown
Ports
Unknown
OS
Unknown
Vulnerable Versions
Linux d3f56c653c65
Linux not down converted
Prerequisites
Unknown
Discovered By
Unknown
PoC Author
Unknown
Metasploit Module
Unknown
Reporter
Unknown

Vendors

  • linux

Products

  • linux kernel
Technical Analysis