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FreeBSD : FreeBSD -- Local privilege escalation via execve(2) TOCTOU race (4b0d0a49-74e1-11f1-958d-bc241121aa0a)

high Nessus Plugin ID 324124

Synopsis

The remote FreeBSD host is missing one or more security-related updates.

Description

The version of FreeBSD installed on the remote host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the 4b0d0a49-74e1-11f1-958d-bc241121aa0a advisory.

 During execve(2) of a SUID binary, the new virtual address space is installed before the process credentials are updated. During this window, a process running as the same user can access the target process's memory via procfs or linprocfs, because the kernel's debugging permission check still saw the original credentials.
 An unprivileged local user can exploit this race to modify the address space of a SUID binary before its credentials are elevated, potentially gaining full control of the affected system.

Tenable has extracted the preceding description block directly from the FreeBSD security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Update the affected packages.

See Also

http://www.nessus.org/u?98218f0d

Plugin Details

Severity: High

ID: 324124

File Name: freebsd_pkg_4b0d0a4974e111f1958dbc241121aa0a.nasl

Version: 1.1

Type: Local

Published: 7/1/2026

Updated: 7/1/2026

Configuration: Enable paranoid mode

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 58.03

CVSS v2

Risk Factor: Medium

Base Score: 5.6

Temporal Score: 4.1

Vector: CVSS2#AV:L/AC:L/Au:N/C:P/I:C/A:N

CVSS Score Source: CVE-2026-49415

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 6.8

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:freebsd:freebsd:freebsd-kernel, cpe:/o:freebsd:freebsd

Required KB Items: Host/local_checks_enabled, Settings/ParanoidReport, Host/FreeBSD/release, Host/FreeBSD/pkg_info

Exploit Ease: No known exploits are available

Patch Publication Date: 7/1/2026

Vulnerability Publication Date: 7/1/2026

Reference Information

CVE: CVE-2026-49415