AI Summary: The bcoles/kernel-exploits repository provides various updated local root exploit implementations targeting vulnerabilities in the Linux kernel, specifically those identified by their CVEs. Each exploit enables privilege escalation through vulnerabilities such as improper memory handling or mismanaged user namespaces, allowing attackers to gain root access under certain conditions. Notable features include detailed exploit descriptions and references to original sources for further investigation.

README

Kernel Exploits

Various kernel exploits

CVE-2021-22555

Linux local root exploit.

Updated version of theflow’s exploit for CVE-2021-22555.

A heap out-of-bounds write affecting Linux since v2.6.19-rc1 was discovered in net/netfilter/x_tables.c. This allows an attacker to gain privileges or cause a DoS (via heap memory corruption) through user name space.

CVE-2019-13272

Linux local root exploit.

Updated version of Jann Horn’s exploit for CVE-2019-13272.

In the Linux kernel before 5.1.17, ptrace_link in kernel/ptrace.c mishandles the recording of the credentials of a process that wants to create a ptrace relationship, which allows local users to obtain root access by leveraging certain scenarios with a parent-child process relationship, where a parent drops privileges and calls execve (potentially allowing control by an attacker). One contributing factor is an object lifetime issue (which can also cause a panic). Another contributing factor is incorrect marking of a ptrace relationship as privileged, which is exploitable through (for example) Polkit’s pkexec helper with PTRACE_TRACEME. NOTE: SELinux deny_ptrace might be a usable workaround in some environments.

CVE-2018-18955

Linux local root exploit.

Wrapper for Jann Horn’s exploit for CVE-2018-18955.

In the Linux kernel 4.15.x through 4.19.x before 4.19.2, map_write() in kernel/user_namespace.c allows privilege escalation because it mishandles nested user namespaces with more than 5 UID or GID ranges. A user who has CAP_SYS_ADMIN in an affected user namespace can bypass access controls on resources outside the namespace, as demonstrated by reading /etc/shadow. This occurs because an ID transformation takes place properly for the namespaced-to-kernel direction but not for the kernel-to-namespaced direction.

CVE-2018-5333

Linux local root exploit.

Updated version of wbowling’s exploit for CVE-2018-5333.

In the Linux kernel through 4.14.13, the rds_cmsg_atomic function in net/rds/rdma.c mishandles cases where page pinning fails or an invalid address is supplied, leading to an rds_atomic_free_op NULL pointer dereference.

CVE-2017-1000112

Linux local root exploit.

Updated version of xairy’s exploit for CVE-2017-1000112.

Linux kernel: Exploitable memory corruption due to UFO to non-UFO path switch. When building a UFO packet with MSG_MORE __ip_append_data() calls ip_ufo_append_data() to append. However in between two send() calls, the append path can be switched from UFO to non-UFO one, which leads to a memory corruption. In case UFO packet lengths exceeds MTU, copy = maxfraglen - skb->len becomes negative on the non-UFO path and the branch to allocate new skb is taken. This triggers fragmentation and computation of fraggap = skb_prev->len - maxfraglen. Fraggap can exceed MTU, causing copy = datalen - transhdrlen - fraggap to become negative. Subsequently skb_copy_and_csum_bits() writes out-of-bounds. A similar issue is present in IPv6 code. The bug was introduced in e89e9cf539a2 ("[IPv4/IPv6]: UFO Scatter-gather approach") on Oct 18 2005.

CVE-2017-7308

Linux local root exploit.

Updated version of xairy’s exploit for CVE-2017-7308.

The packet_set_ring function in net/packet/af_packet.c in the Linux kernel through 4.10.6 does not properly validate certain block-size data, which allows local users to cause a denial of service (integer signedness error and out-of-bounds write), or gain privileges (if the CAP_NET_RAW capability is held), via crafted system calls.

CVE-2016-9793

Linux local root exploit.

Updated version of xairy’s exploit for CVE-2016-9793.

The sock_setsockopt function in net/core/sock.c in the Linux kernel before 4.8.14 mishandles negative values of sk_sndbuf and sk_rcvbuf, which allows local users to cause a denial of service (memory corruption and system crash) or possibly have unspecified other impact by leveraging the CAP_NET_ADMIN capability for a crafted setsockopt system call with the (1) SO_SNDBUFFORCE or (2) SO_RCVBUFFORCE option.

CVE-2016-8655

Linux local root exploit.

Updated version of rebel’s exploit for CVE-2016-8655.

Race condition in net/packet/af_packet.c in the Linux kernel through 4.8.12 allows local users to gain privileges or cause a denial of service (use-after-free) by leveraging the CAP_NET_RAW capability to change a socket version, related to the packet_set_ring and packet_setsockopt functions.