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HIGH

kernel: Out-of-bounds heap access in xfrm

Published Mar 19, 2017

Description

The xfrm_replay_verify_len function in net/xfrm/xfrm_user.c in the Linux kernel through 4.10.6 does not validate certain size data after an XFRM_MSG_NEWAE update, which allows local users to obtain root privileges or cause a denial of service (heap-based out-of-bounds access) by leveraging the CAP_NET_ADMIN capability, as demonstrated during a Pwn2Own competition at CanSecWest 2017 for the Ubuntu 16.10 linux-image-* package 4.8.0.41.52.

Affected products

Remediation

Red Hat 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.

Metrics

Weaknesses (1)

References (19)

Change history (0)

No recorded changes yet.

Sources
CVE.org / MITRE
Status PUBLISHED
Assigner mitre
Published Mar 19, 2017
Updated Aug 5, 2024
Reserved Mar 19, 2017
NVD
Status Modified
Modified Jun 17, 2026
Red Hat
Severity Important
Public date Mar 29, 2017