Out-of-bounds kernel heap access vulnerability was found in xfrm, kernel's IP framework for transforming packets. An error dealing with netlink messages from unprivileged user leads to arbitrary read/write and privilege escalation. Public disclosure on oss-security: http://openwall.com/lists/oss-security/2017/03/29/2 http://seclists.org/oss-sec/2017/q1/689 Upstream patches: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=677e806da4d916052585301785d847c3b3e6186a https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f843ee6dd019bcece3e74e76ad9df0155655d0df
Created attachment 1265661 [details] Proposed patch
Acknowledgments: Name: Chaitin Security Research Lab
Created attachment 1265674 [details] Proposed patch pt. 2
Statement: This issue does not affect the Linux kernel packages as shipped with Red Hat Enterprise Linux 5, 6 as the code with the flaw is not present in the products listed. This issue affects the Linux kernel packages as shipped with Red Hat Enterprise Linux 7 and MRG-2. In a default or common use of Red Hat Enterprise Linux 7 and MRG-2 this issue does not allow an unprivileged local or remote user to elevate their privileges on the system. In order to exploit this issue the attacker needs CAP_NET_ADMIN capability, which needs to be granted especially by the administrator to the attacker's process. This in turn requires granting CAP_NET_ADMIN capability to the process' binary and/or attacker's account. Another possibility to obtain CAP_NET_ADMIN capability in Red Hat Enterprise Linux 7 for an attacker is running a process inside a user+network namespace with mapped root privileges inside the namespace. Since Red Hat Enterprise Linux 7 does not have unprivileged user namespaces enabled by default, local or remote unprivileged users also cannot abuse namespaces to grant this capability to themselves and elevate their privileges. Given the severity of this issue, future Linux kernel updates for the Red Hat Enterprise Linux 7 and MRG-2 products are planned to address it.
Created kernel tracking bugs for this issue: Affects: fedora-all [bug 1437469]
This issue has been addressed in the following products: Red Hat Enterprise MRG 2 Via RHSA-2017:2918 https://access.redhat.com/errata/RHSA-2017:2918
This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Via RHSA-2017:2930 https://access.redhat.com/errata/RHSA-2017:2930
This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Via RHSA-2017:2931 https://access.redhat.com/errata/RHSA-2017:2931
This issue has been addressed in the following products: Red Hat Enterprise Linux 7.3 Telco Extended Update Support Red Hat Enterprise Linux 7.3 Advanced Update Support Red Hat Enterprise Linux 7.3 Update Services for SAP Solutions Via RHSA-2019:4159 https://access.redhat.com/errata/RHSA-2019:4159