DMIT Server Security Audit Summary | Generated by AI

Home 2026.05

Now I have a complete picture. Here’s the security audit of your DMIT server at 69.63.0.0:

============================================================ SECURITY AUDIT: 69.63.0.0 (DMIT Los Angeles) Date: 2026-05-24 ============================================================

OPEN PORTS

Only 1 port open out of 65535:

22/tcp SSH OpenSSH 9.6p1 Ubuntu 3ubuntu13.14

All other ports: filtered (firewall drops packets silently)

============================================================ SSH CONFIGURATION ANALYSIS ============================================================

GOOD (hardened): ✓ Publickey-only auth — no password authentication ✓ Modern KEX: sntrup761x25519-sha512 (post-quantum!), curve25519-sha256 ✓ Strong ciphers: chacha20-poly1305, aes256-gcm (no CBC mode) ✓ Strong MACs: all ETM variants preferred (encrypt-then-MAC) ✓ ED25519 + ECDSA host keys (no RSA key — good) ✓ kex-strict-s-v00@openssh.com (Terrapin attack mitigation) ✓ No SSHv1 support ✓ zlib compression only on request (not forced)

MINOR CONCERNS: ⚠ hmac-sha1 and umac-64 still offered as MAC algorithms — Not critical (client chooses strongest), but could be removed from server config for defense-in-depth ⚠ ecdh-sha2-nistp256/384/521 still offered — NIST curves have trust issues in some threat models — curve25519 is preferred, so low practical risk ⚠ zlib@openssh.com compression enabled — Compression can leak info via compression ratio attacks (similar to CRIME/BREACH). Disable if not needed.

============================================================ VULNERABILITY ASSESSMENT ============================================================

CRITICAL — CVE-2024-6387 (regreSSHion): OpenSSH 9.6p1 IS in the vulnerable range (8.5p1 to 9.7p1). This is a race condition in the SIGALRM handler during LoginGraceTime. Can lead to unauthenticated remote code execution as root on glibc-based Linux systems.

HOWEVER: Exploit requires winning a race condition with ~10^8 attempts on 32-bit, practically infeasible on 64-bit. Ubuntu may have backported the fix — check with: dpkg -l openssh-server apt changelog openssh-server | grep -i regression

MITIGATION: Upgrade to OpenSSH 9.8p1+ or apply Ubuntu patch.

LOW — OpenSSH 9.6 has a few other low-severity issues:

============================================================ NETWORK / FIREWALL ============================================================

✓ Excellent attack surface — only SSH exposed ✓ All other ports silently dropped (not rejected) — Stealth mode, doesn’t reveal open/closed state ✓ No web server, no database, no proxy ports exposed ✓ No UDP services detectable (hysteria2 runs but filtered)

The hysteria2 proxy port appears to be behind a firewall or only accepting connections from specific sources.

============================================================ RECOMMENDATIONS (prioritized) ============================================================

  1. CHECK regreSSHion patch status: ssh lzw@69.63.0.0 “apt changelog openssh-server 2>/dev/null | head -20” Or: ssh lzw@69.63.0.0 “dpkg -s openssh-server | grep Version”

  2. ADD fail2ban if not already running: sudo apt install fail2ban sudo systemctl enable fail2ban

  3. DISABLE weak MACs in /etc/ssh/sshd_config: MACs hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,umac-128-etm@openssh.com

  4. DISABLE compression if not needed: Compression no

  5. ADD connection rate limiting: MaxStartups 10:30:60 LoginGraceTime 30

  6. CONSIDER port knocking or changing SSH port: Not critical with pubkey-only auth, but reduces log noise.

============================================================ BOTTOM LINE ============================================================

This server is well-hardened. The attack surface is minimal (only SSH), auth is pubkey-only, crypto is modern, and the firewall is tight. The main concern is the regreSSHion CVE (CVE-2024-6387) — verify Ubuntu has patched it. Everything else is low-risk.

You can’t “break in” from the outside without the private key. The only real attack vector is the regreSSHion race condition, which is practically infeasible on 64-bit systems.

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