Materialized exploit

CVE-2016-3134

CRITICAL

1 public exploit(s) for this CVE, 1 materialized with their code.

For defensive research only. Only test on systems you own or have written authorization for. Unauthorized access is illegal.

ExploitDB dos linux Verified

Source

Linux Kernel 3.10/3.18 /4.4 - Netfilter IPT_SO_SET_REPLACE Memory Corruption

By Google Security Research

How to test this exploit

Denial of service: sends malformed input to crash the service. Test in an isolated VM, the effect is destructive.

Code txt

Source: https://code.google.com/p/google-security-research/issues/detail?id=758

A memory corruption vulnerability exists in the IPT_SO_SET_REPLACE ioctl in the netfilter code for iptables support. This ioctl is can be triggered by an unprivileged user on PF_INET sockets when unprivileged user namespaces are available (CONFIG_USER_NS=y). Android does not enable this option, but desktop/server distributions and Chrome OS will commonly enable this to allow for containers support or sandboxing.

In the mark_source_chains function (net/ipv4/netfilter/ip_tables.c) it is possible for a user-supplied ipt_entry structure to have a large next_offset field. This field is not bounds checked prior to writing a counter value at the supplied offset:

newpos = pos + e->next_offset;
...
e = (struct ipt_entry *) (entry0 + newpos);
e->counters.pcnt = pos;

This means that an out of bounds 32-bit write can occur in a 64kb range from the allocated heap entry, with a controlled offset and a partially controlled write value ("pos") or zero. The attached proof-of-concept (netfilter_setsockopt_v3.c) triggers the corruption multiple times to set adjacent heap structures to zero.

This issue affects (at least) kernel versions 3.10, 3.18 and 4.4. It appears that a similar codepath is accessible via arp_tables.c/ARPT_SO_SET_REPLACE as well.

Furthermore, a recent refactoring cof this codepath (https://github.com/torvalds/linux/commit/2e4e6a17af35be359cc8f1c924f8f198fbd478cc) introduced an integer overflow in xt_alloc_table_info, which on 32-bit systems can lead to small structure allocation and a copy_from_user based heap corruption. The attached proof-of-concept (netfilter_setsockopt_v4.c) triggers this issue on 4.4.

Correction: IPT_SO_SET_REPLACE is reached via setsockopt, not ioctl!


Proof of Concept:
https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/39545.zip