Vulnerabilities

In Sudo through 1.9.17p2 before 3e474c2, a failure of a setuid, setgid, or setgroups call, during a privilege drop before running the mailer, is not a fatal error and can lead to privilege escalation.

Sudo before 1.9.17p1 mishandles the --chroot option: when sudo runs chrooted, it loads /etc/nsswitch.conf from the user-controlled chroot directory rather than the trusted system copy. A local user who can invoke sudo with --chroot can plant a crafted nsswitch.conf (and the NSS libraries it references) in that directory, causing sudo to load untrusted functionality as root. Successful exploitation grants full root privileges on the host, and any Linux deployment running an unpatched sudo is affected, including Ubuntu, Debian, Red Hat Enterprise Linux, SUSE and openSUSE products per the CPE data. The vulnerability is confirmed exploited in the wild: CISA added it to the Known Exploited Vulnerabilities catalog on 2025-09-29 (ransomware association not yet reported), and EPSS assigns a high 59.4% probability of exploitation within 30 days. Public proof-of-concept references are already available from the researchers who disclosed the flaw.

Do: Upgrade Sudo to 1.9.17p1 or later, or apply your distribution's updated sudo packages (Ubuntu, Debian, Red Hat Enterprise Linux, SUSE and openSUSE have issued patches); the same update also fixes the related local privilege escalation CVE-2025-32462. Until patched, remove or restrict the -R/--chroot option in sudoers policies and identify local users permitted to run sudo with chroot, and audit installed sudo versions across servers and container images. Federal agencies must satisfy the CISA KEV required action, including applicable BOD 22-01 guidance for cloud services.

Sudo before 1.9.17p1, when used with a sudoers file that specifies a host that is neither the current host nor ALL, allows listed users to execute commands on unintended machines.

A flaw was found in sudo in the handling of ipa_hostname, where ipa_hostname from /etc/sssd/sssd.conf was not propagated in sudo. Therefore, it leads to privilege mismanagement vulnerability in applications, where client hosts retain privileges even after retracting them.

Sudo before 1.9.15 might allow row hammer attacks (for authentication bypass or privilege escalation) because application logic sometimes is based on not equaling an error value (instead of equaling a success value), and because the values do not resist flips of a single bit.

Sudo before 1.9.13 does not escape control characters in sudoreplay output.

Sudo before 1.9.13p2 has a double free in the per-command chroot feature.

In Sudo before 1.9.12p2, the sudoedit (aka -e) feature mishandles extra arguments passed in the user-provided environment variables (SUDO_EDITOR, VISUAL, and EDITOR), allowing a local attacker to append arbitrary entries to the list of files to process. This can lead to privilege escalation. Affected versions are 1.8.0 through 1.9.12.p1. The problem exists because a user-specified editor may contain a "--" argument that defeats a protection mechanism, e.g., an EDITOR='vim -- /path/to/extra/file' value.

Sudo 1.8.0 through 1.9.12, with the crypt() password backend, contains a plugins/sudoers/auth/passwd.c array-out-of-bounds error that can result in a heap-based buffer over-read. This can be triggered by arbitrary local users with access to Sudo by entering a password of seven characters or fewer. The impact could vary depending on the system libraries, compiler, and processor architecture.

CVE-2021-3156 is an off-by-one error (CWE-193) in the Unix Sudo utility that causes a heap-based buffer overflow (CWE-122) in Sudo's handling of command-line arguments. It is triggered locally when an unprivileged user invokes Sudo with specially crafted arguments, requiring no special privileges or non-default configuration. A successful exploit allows the attacker to execute arbitrary code as root, achieving full local privilege escalation on the host. Any Linux, Unix, or other system running a vulnerable version of Sudo is affected, and because Sudo ships by default on virtually all such systems the potential footprint is enormous. The flaw is listed in CISA's Known Exploited Vulnerabilities catalog (added 2022-04-06) and carries a 100% EPSS probability of exploitation within 30 days, indicating active in-the-wild exploitation, though specific ransomware use is unknown.

Do: Upgrade Sudo to a patched release (1.9.5p2 or later, or the vendor-supplied update for your distribution) per vendor instructions, as required by the CISA KEV listing. Audit all Unix-like hosts by checking the installed Sudo version through your package manager and prioritize patching multi-user and internet-facing servers. Restricting local shell access and monitoring for anomalous Sudo invocations can reduce risk while patching completes.

selinux_edit_copy_tfiles in sudoedit in Sudo before 1.9.5 allows a local unprivileged user to gain file ownership and escalate privileges by replacing a temporary file with a symlink to an arbitrary file target. This affects SELinux RBAC support in permissive mode. Machines without SELinux are not vulnerable.

In Sudo before 1.8.26, if pwfeedback is enabled in /etc/sudoers, users can trigger a stack-based buffer overflow in the privileged sudo process. (pwfeedback is a default setting in Linux Mint and elementary OS; however, it is NOT the default for upstream and many other packages, and would exist only if enabled by an administrator.) The attacker needs to deliver a long string to the stdin of getln() in tgetpass.c.

Sudo through 1.8.29 allows local users to escalate to root if they have write access to file descriptor 3 of the sudo process. This occurs because of a race condition between determining a uid, and the setresuid and openat system calls. The attacker can write "ALL ALL=(ALL) NOPASSWD:ALL" to /proc/#####/fd/3 at a time when Sudo is prompting for a password. NOTE: This has been disputed due to the way Linux /proc works. It has been argued that writing to /proc/#####/fd/3 would only be viable if you had permission to write to /etc/sudoers. Even with write permission to /proc/#####/fd/3, it would not help you write to /etc/sudoers

In Sudo before 1.8.28, an attacker with access to a Runas ALL sudoer account can bypass certain policy blacklists and session PAM modules, and can cause incorrect logging, by invoking sudo with a crafted user ID. For example, this allows bypass of !root configuration, and USER= logging, for a "sudo -u \#$((0xffffffff))" command.

sudo before version 1.8.18p1 is vulnerable to a bypass in the sudo noexec restriction if application run via sudo executed wordexp() C library function with a user supplied argument. A local user permitted to run such application via sudo with noexec restriction could possibly use this flaw to execute arbitrary commands with elevated privileges.

Todd Miller's sudo version 1.8.20p1 and earlier is vulnerable to an input validation (embedded newlines) in the get_process_ttyname() function resulting in information disclosure and command execution.