CVE-2015-3204 malicious payload causing IKE daemon restart
This alert (and any possible updates) is available at the following URLs:
The Libreswan Project was notified by Javantea <email@example.com> of two
vulnerabilities found by fuzzing IKEv1 payloads. The malicious IKE packet
causes an unexpected state in the IKE daemon resulting in passert() calls
terminating and restarting the IKE daemon. No remote code execution is
Vulnerable versions: libreswan 3.9 up to version 3.12
Not vulnerable : libreswan 3.13 and newer
If you cannot upgrade to 3.13, please see the above link for a patch for
Javantea used a custom IKE fuzzer to test libreswan and found two issues
resulting in the libreswan IKE daemon to hit a passert() and restart.
By setting unassigned bits of the IPSEC DOI value, an error message
string would be printed with string names as bit numbers. Printing 32 of
these would cause the internal buffer "bitnamesbuf" to be too small. This
buffer is truncated properly in the non-vulnerable versions. A generic
jam_str() function was added to these protections, but it would passert()
if not given at least a buffer length of 1 (to add a NULL to terminate
the string). However, the filled in string would have no more space for
the additional 1 character to be added. The passert() would cause the IKE
daemon to restart.
By setting the next payload value to ISAKMP_NEXT_SAK (used by old Cisco
VPN servers to signal NAT-Traversal payloads), the libreswan daemon would
attempt to interpret this payload as a NAT-D payload. However, it did not
properly do so, causing a passert() which would restart the IKE daemon.
This denial of service can be launched by anyone using a single IKE packet.
No authentication credentials are required. No remote code execution is
possible through this vulnerability. Libreswan automatically restarts when
There is no workaround. Either upgrade or use the supplied patch in the
above listed resource URL.
I will commit a version bump later today.
net-misc/libreswan-3.13 has been added to the tree, and may be stabilized.
libreswan 3.9 through 3.12 allows remote attackers to cause a denial of
service (daemon restart) via an IKEv1 packet with (1) unassigned bits set in
the IPSEC DOI value or (2) the next payload value set to ISAKMP_NEXT_SAK.
Arches, please stabilize:
Stable targets: amd64 x86
Maintainer(s), please cleanup.
Security, please vote.
Arches and Maintainer(s), Thank you for your work.
GLSA Vote: Yes
Maintainer(s), please drop the vulnerable version(s).
Cleanup done. Already assigned to a GLSA.
This issue was resolved and addressed in
GLSA 201603-13 at https://security.gentoo.org/glsa/201603-13
by GLSA coordinator Kristian Fiskerstrand (K_F).