CVE-2017-1000111: Race Condition
A race condition issue was found in the way the raw packet sockets implementation in the Linux kernel networking subsystem handled synchronization. A local user able to open a raw packet socket (requires the CAPNETRAW capability) could use this to waste resources in the kernels ring buffer or possibly cause a read-out-of-bounds on the heap possibly panicking the machine.
In a default or common use of Red Hat Enterprise Linux 6 and 7 this issue does not allow an unprivileged local user to use this functionality.
In order to exploit this issue the attacker needs CAPNETRAW capability, which needs to be granted by the administrator to the attacker's account. Since Red Hat Enterprise Linux does not have unprivileged user namespaces enabled by default, local unprivileged users also cannot abuse namespaces to grant this capability.
Upstream patch: http://patchwork.ozlabs.org/patch/800274/
Other sources
Linux kernel: heap out-of-bounds in AFPACKET sockets. This new issue is analogous to previously disclosed CVE-2016-8655. In both cases, a socket option that changes socket state may race with safety checks in packetsetring. Previously with PACKETVERSION. This time with PACKETRESERVE. The solution is similar: lock the socket for the update. This issue may be exploitable, we did not investigate further. As this issue affects PFPACKET sockets, it requires CAPNETRAW in the process namespace. But note that with user namespaces enabled, any process can create a namespace in which it has CAPNETRAW.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2017-1000111?
CVE-2017-1000111 has a medium severity rating, indicating a moderate risk to systems.
How do I fix CVE-2017-1000111?
To fix CVE-2017-1000111, users should upgrade the Linux kernel to a version that includes the appropriate patches as specified by their distribution.
What systems are affected by CVE-2017-1000111?
CVE-2017-1000111 affects various versions of the Linux kernel, particularly those below 4.19.249-2 and those within specific ranges up to 6.6.9-1.
Can CVE-2017-1000111 be exploited remotely?
CVE-2017-1000111 cannot be exploited remotely as it requires local access to exploit the vulnerability.
What capabilities are required to exploit CVE-2017-1000111?
To exploit CVE-2017-1000111, a local user must have the CAP_NET_RAW capability to open a raw packet socket.