Bug 1232320 (CVE-2015-3240) - CVE-2015-3240 libreswan / openswan: denial of service via IKE daemon restart when receiving a bad DH gx value
Summary: CVE-2015-3240 libreswan / openswan: denial of service via IKE daemon restart ...
Alias: CVE-2015-3240
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
Depends On: 1256802 1256803 1259206 1259207 1259208 1259209
Blocks: 1232321
TreeView+ depends on / blocked
Reported: 2015-06-16 13:25 UTC by Vasyl Kaigorodov
Modified: 2019-09-29 13:33 UTC (History)
4 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
A flaw was discovered in the way Libreswan's IKE daemon processed IKE KE payloads. A remote attacker could send specially crafted IKE payload with a KE payload of g^x=0 that, when processed, would lead to a denial of service (daemon crash).
Clone Of:
Last Closed: 2015-11-20 07:15:14 UTC

Attachments (Terms of Use)

System ID Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2015:1979 normal SHIPPED_LIVE Moderate: libreswan security and enhancement update 2015-11-04 13:37:20 UTC

Description Vasyl Kaigorodov 2015-06-16 13:25:25 UTC
Paul Wouters of Red Hat reported a denial of service issue in libreswan/openswan:

If the peer sends us a DH gx value of 0, openswan/libreswan passes it to the NSS library, which returns NULL because it cannot perform DH with 0, which hits a passert() in the swan code. An attacker can keep connecting to the service and perform the bad DH, causing a denial of service.

Comment 3 Paul Wouters 2015-08-25 04:51:18 UTC
This issue is now public: https://libreswan.org/security/CVE-2015-3240/

Comment 4 Adam Mariš 2015-08-25 13:22:23 UTC
Created libreswan tracking bugs for this issue:

Affects: epel-all [bug 1256803]

Comment 5 Fedora Update System 2015-08-26 17:25:10 UTC
libreswan-3.15-1.fc21 has been pushed to the Fedora 21 testing repository. If problems still persist, please make note of it in this bug report.\nIf you want to test the update, you can install it with \n su -c 'yum --enablerepo=updates-testing update libreswan'. You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2015-14179

Comment 6 Paul Wouters 2015-08-27 13:54:18 UTC
note that using libreswan-3,15 you can test sending a bad g^x by running:

ipsec start
ipsec auto --add connname
ipsec whack --debug-all --impair-send-zero-gx
ipsec auto --up connname

Comment 9 Martin Prpič 2015-11-03 07:44:26 UTC

This issue was discovered by Paul Wouters of Red Hat.

Comment 10 Tomas Hoger 2015-11-03 12:04:22 UTC
External References:


Comment 11 errata-xmlrpc 2015-11-04 08:37:41 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2015:1979 https://rhn.redhat.com/errata/RHSA-2015-1979.html

Note You need to log in before you can comment on or make changes to this bug.