CVE-2016-4557

high

Published 2016-05-23 · Modified 2026-05-06

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CVSS v3

7.8

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS v4 NEW

—

not yet in upstream

VIR risk

8.8

Description

The replace_map_fd_with_map_ptr function in kernel/bpf/verifier.c in the Linux kernel before 4.5.5 does not properly maintain an fd data structure, which allows local users to gain privileges or cause a denial of service (use-after-free) via crafted BPF instructions that reference an incorrect file descriptor.

Predictions

Exploit likelihood

100%

Patch ETA

—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

Exploits

Public proof-of-concept code below. AS-IS, for defenders and authorised testing only.

Exploit-DB

EDB-40759 local linux verified

Metasploit · 2016-11-14

Linux Kernel 4.4 (Ubuntu 16.04) - 'BPF' Local Privilege Escalation (Metasploit)

Source code queued for fetch — refresh in a moment.

EDB-39772 local linux verified

Google Security Research · 2016-05-04

Linux Kernel 4.4.x (Ubuntu 16.04) - 'double-fdput()' bpf(BPF_PROG_LOAD) Privilege Escalation

Source code queued for fetch — refresh in a moment.

Metasploit modules

exploit_linux/local/bpf_priv_esc rank 400

Linux BPF doubleput UAF Privilege Escalation

Source fetch failed: fetch_error — view the original via the link above.

OS impact

Linux kernel Affected 1 release

Version	Status	Fixed in
—	Affected	`4.4.11`

SUSE Affected 1 release

Version	Status	Fixed in
—	Affected	—

Debian Fixed 5 releases

Version	Status	Fixed in
trixie	Fixed	`4.5.3-1`
sid	Fixed	`4.5.3-1`
forky	Fixed	`4.5.3-1`
bullseye	Fixed	`4.5.3-1`
bookworm	Fixed	`4.5.3-1`

References

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.