CVE-2018-17204 - Reachable Assertion

Severity

40%

Complexity

80%

Confidentiality

48%

An issue was discovered in Open vSwitch (OvS) 2.7.x through 2.7.6, affecting parse_group_prop_ntr_selection_method in lib/ofp-util.c. When decoding a group mod, it validates the group type and command after the whole group mod has been decoded. The OF1.5 decoder, however, tries to use the type and command earlier, when it might still be invalid. This causes an assertion failure (via OVS_NOT_REACHED). ovs-vswitchd does not enable support for OpenFlow 1.5 by default.

An issue was discovered in Open vSwitch (OvS) 2.7.x through 2.7.6, affecting parse_group_prop_ntr_selection_method in lib/ofp-util.c. When decoding a group mod, it validates the group type and command after the whole group mod has been decoded. The OF1.5 decoder, however, tries to use the type and command earlier, when it might still be invalid. This causes an assertion failure (via OVS_NOT_REACHED). ovs-vswitchd does not enable support for OpenFlow 1.5 by default.

CVSS 3.0 Base Score 4.3. CVSS Attack Vector: network. CVSS Attack Complexity: low. CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L).

CVSS 2.0 Base Score 4. CVSS Attack Vector: network. CVSS Attack Complexity: low. CVSS Vector: (AV:N/AC:L/Au:S/C:N/I:N/A:P).

Demo Examples

Reachable Assertion

CWE-617

In the excerpt below, an AssertionError (an unchecked exception) is thrown if the user hasn't entered an email address in an HTML form.


               
assert email != null;

Overview

First reported 6 years ago

2018-09-19 16:29:00

Last updated 5 years ago

2019-10-03 00:03:00

Affected Software

Red Hat OpenStack 10

10

Red Hat OpenStack 13.0

13.0

Red Hat Virtualization 4.0

4.0

Canonical Ubuntu Linux 16.04 LTS (Long-Term Support)

16.04

Canonical Ubuntu Linux 18.04 LTS Edition

18.04

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