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strongSwan VPN charon server vulnerable to buffer underflow

Vulnerability Note VU#338343

Original Release Date: 2018-05-23 | Last Revised: 2018-06-13

Overview

strongSwan VPN's charon server prior to version 5.6.3 does not check packet length and may allow buffer underflow, resulting in denial of service.

Description

CWE-124: Buffer Underwrite ('Buffer Underflow') - CVE-2018-5388

In stroke_socket.c, a missing packet length check could allow a buffer underflow, which may lead to resource exhaustion and denial of service while reading from the socket.

According to the vendor, an attacker must typically have local root permissions to access the socket. However, other accounts and groups such as the vpn group (if capability dropping in enabled, for example) may also have sufficient permissions, but this configuration does not appear to be the default behavior.

Impact

A remote attacker with local user credentials (possibly a normal user in the vpn group, or root) may be able to underflow the buffer and cause a denial of service.

Solution

Apply an update

StrongSwan version 5.6.3 and above contain a patch for this issue.

Vendor Information

338343
 
Affected   Unknown   Unaffected

SUSE Linux

Notified:  May 23, 2018 Updated:  May 24, 2018

Statement Date:   May 24, 2018

Status

  Affected

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

An updated version of strongSwan is expected to become available shortly. Further details can be read in the advisory.

Vendor References

https://www.suse.com/security/cve/CVE-2018-5388/ https://bugzilla.suse.com/show_bug.cgi?id=1094462

strongSwan

Notified:  March 21, 2018 Updated:  May 24, 2018

Status

  Affected

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

StrongSwan version 5.6.3 and above contain a patch for this issue.

ASP Linux

Notified:  May 23, 2018 Updated:  May 23, 2018

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Alpine Linux

Notified:  May 23, 2018 Updated:  May 23, 2018

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Arch Linux

Notified:  May 23, 2018 Updated:  May 23, 2018

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Arista Networks, Inc.

Notified:  May 23, 2018 Updated:  May 23, 2018

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

CentOS

Notified:  May 23, 2018 Updated:  May 23, 2018

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

CoreOS

Notified:  May 23, 2018 Updated:  May 23, 2018

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Debian GNU/Linux

Notified:  May 23, 2018 Updated:  May 23, 2018

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

ENEA

Notified:  May 23, 2018 Updated:  May 23, 2018

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Fedora Project

Notified:  May 23, 2018 Updated:  May 23, 2018

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Geexbox

Notified:  May 23, 2018 Updated:  May 23, 2018

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Gentoo Linux

Notified:  May 23, 2018 Updated:  May 23, 2018

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

HomeSeer

Notified:  May 23, 2018 Updated:  May 23, 2018

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Micro Focus

Notified:  May 23, 2018 Updated:  May 23, 2018

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

MontaVista Software, Inc.

Notified:  May 23, 2018 Updated:  May 23, 2018

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Openwall GNU/*/Linux

Notified:  May 23, 2018 Updated:  May 23, 2018

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Red Hat, Inc.

Notified:  May 23, 2018 Updated:  May 23, 2018

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Slackware Linux Inc.

Notified:  May 23, 2018 Updated:  May 23, 2018

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Tizen

Notified:  May 23, 2018 Updated:  May 23, 2018

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Turbolinux

Notified:  May 23, 2018 Updated:  May 23, 2018

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Ubuntu

Notified:  May 23, 2018 Updated:  May 23, 2018

Status

  Unknown

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.


CVSS Metrics

Group Score Vector
Base 4.9 AV:N/AC:H/Au:S/C:N/I:N/A:C
Temporal 3.8 E:POC/RL:OF/RC:C
Environmental 3.9 CDP:ND/TD:ND/CR:ND/IR:ND/AR:ND

References

Credit

Thanks to Kevin Backhouse of Semmle Ltd. for reporting this vulnerability.

This document was written by Garret Wassermann.

Other Information

CVE IDs: CVE-2018-5388
Date Public: 2018-05-22
Date First Published: 2018-05-23
Date Last Updated: 2018-06-13 16:07 UTC
Document Revision: 39

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