CVE-2016-8655

Impact:
Important
Public Date:
2016-12-06
CWE:
CWE-362->CWE-416
Bugzilla:
1400019: CVE-2016-8655 kernel: Race condition in packet_set_ring leads to use after free
A race condition issue leading to a use-after-free flaw was found in the way the raw packet sockets implementation in the Linux kernel networking subsystem handled synchronization while creating the TPACKET_V3 ring buffer. A local user able to open a raw packet socket (requires the CAP_NET_RAW capability) could use this flaw to elevate their privileges on the system.

Find out more about CVE-2016-8655 from the MITRE CVE dictionary dictionary and NIST NVD.

Statement

This issue does not affect Red Hat Enterprise Linux 5 and 6.

This issue does affect Red Hat Enterprise Linux 7 and Red Hat Enterprise MRG 2. Future updates for the respective releases will address this issue.

In a default or common use of Red Hat Enterprise Linux 7 this issue does not allow an unprivileged local user elevate their privileges on the system.

In order to exploit this issue the attacker needs CAP_NET_RAW capability, which needs to be granted by the administrator to the attacker's account. Since Red Hat Enterprise Linux 7 does not have unprivileged user namespaces enabled by default, local unprivileged users also cannot abuse namespaces to grant this capability to themselves and elevate their privileges.

CVSS v2 metrics

Base Score 6.6
Base Metrics AV:L/AC:M/Au:S/C:C/I:C/A:C
Access Vector Local
Access Complexity Medium
Authentication Single
Confidentiality Impact Complete
Integrity Impact Complete
Availability Impact Complete

CVSS v3 metrics

CVSS3 Base Score 7
CVSS3 Base Metrics CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack Vector Local
Attack Complexity High
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality High
Integrity Impact High
Availability Impact High

Find out more about Red Hat support for the Common Vulnerability Scoring System (CVSS).

Red Hat Security Errata

Platform Errata Release Date
Red Hat Enterprise Linux 7 (kernel) RHSA-2017:0386 2017-03-02
Red Hat Enterprise Linux for Real Time for NFV (v. 7) (kernel-rt) RHSA-2017:0387 2017-03-02
MRG Grid for RHEL 6 Server v.2 (kernel-rt) RHSA-2017:0402 2017-03-02

Affected Packages State

Platform Package State
Red Hat Enterprise MRG 2 realtime-kernel Affected
Red Hat Enterprise Linux 6 kernel Not affected
Red Hat Enterprise Linux 5 kernel Not affected

Acknowledgements

Red Hat would like to thank Philip Pettersson for reporting this issue.

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