# ssh-audit [![Build Status](https://travis-ci.org/jtesta/ssh-audit.svg?branch=master)](https://travis-ci.org/jtesta/ssh-audit) **ssh-audit** is a tool for ssh server & client configuration auditing. [jtesta/ssh-audit](https://github.com/jtesta/ssh-audit/) (v2.0+) is the updated and maintained version of ssh-audit forked from [arthepsy/ssh-audit](https://github.com/arthepsy/ssh-audit) (v1.x) due to inactivity. ## Features - SSH1 and SSH2 protocol server support; - analyze SSH client configuration; - grab banner, recognize device or software and operating system, detect compression; - gather key-exchange, host-key, encryption and message authentication code algorithms; - output algorithm information (available since, removed/disabled, unsafe/weak/legacy, etc); - output algorithm recommendations (append or remove based on recognized software version); - output security information (related issues, assigned CVE list, etc); - analyze SSH version compatibility based on algorithm information; - historical information from OpenSSH, Dropbear SSH and libssh; - policy scans to ensure adherence to a hardened/standard configuration; - runs on Linux and Windows; - no dependencies ## Usage ``` usage: ssh-audit.py [options] -h, --help print this help -1, --ssh1 force ssh version 1 only -2, --ssh2 force ssh version 2 only -4, --ipv4 enable IPv4 (order of precedence) -6, --ipv6 enable IPv6 (order of precedence) -b, --batch batch output -c, --client-audit starts a server on port 2222 to audit client software config (use -p to change port; use -t to change timeout) -j, --json JSON output -l, --level= minimum output level (info|warn|fail) -L, --list-policies list all the official, built-in policies --lookup= looks up an algorithm(s) without connecting to a server -M, --make-policy= creates a policy based on the target server (i.e.: the target server has the ideal configuration that other servers should adhere to) -n, --no-colors disable colors -p, --port= port to connect -P, --policy=<"policy name" | policy.txt> run a policy test using the specified policy -t, --timeout= timeout (in seconds) for connection and reading (default: 5) -T, --targets= a file containing a list of target hosts (one per line, format HOST[:PORT]) -v, --verbose verbose output ``` * if both IPv4 and IPv6 are used, order of precedence can be set by using either `-46` or `-64`. * batch flag `-b` will output sections without header and without empty lines (implies verbose flag). * verbose flag `-v` will prefix each line with section type and algorithm name. * an exit code of 0 is returned when all algorithms are considered secure (for a standard audit), or when a policy check passes (for a policy audit). Basic server auditing: ``` ssh-audit localhost ssh-audit 127.0.0.1 ssh-audit 127.0.0.1:222 ssh-audit ::1 ssh-audit [::1]:222 ``` To run a standard audit against many servers (place targets into servers.txt, one on each line in the format of `HOST[:PORT]`): ``` ssh-audit -T servers.txt ``` To audit a client configuration (listens on port 2222 by default; connect using `ssh -p 2222 anything@localhost`): ``` ssh-audit -c ``` To audit a client configuration, with a listener on port 4567: ``` ssh-audit -c -p 4567 ``` To list all official built-in policies (hint: use resulting file paths with `-P`/`--policy`): ``` ssh-audit -L ``` To run a policy audit against a server: ``` ssh-audit -P ["policy name" | path/to/server_policy.txt] targetserver ``` To run a policy audit against a client: ``` ssh-audit -c -P ["policy name" | path/to/client_policy.txt] ``` To run a policy audit against many servers: ``` ssh-audit -T servers.txt -P ["policy name" | path/to/server_policy.txt] ``` To create a policy based on a target server (which can be manually edited; see official built-in policies for syntax examples): ``` ssh-audit -M new_policy.txt targetserver ``` ### Server Standard Audit Example Below is a screen shot of the standard server-auditing output when connecting to an unhardened OpenSSH v5.3 service: ![screenshot](https://user-images.githubusercontent.com/2982011/64388792-317e6f80-d00e-11e9-826e-a4934769bb07.png) ### Server Policy Audit Example Below is a screen shot of the policy auditing output when connecting to an un-hardened Ubuntu Server 20.04 machine: ![screenshot](https://user-images.githubusercontent.com/2982011/94370881-95178700-00c0-11eb-8705-3157a4669dc0.png) After applying the steps in the hardening guide (see below), the output changes to the following: ![screenshot](https://user-images.githubusercontent.com/2982011/94370873-87620180-00c0-11eb-9a59-469f61a56ce1.png) ### Client Standard Audit Example Below is a screen shot of the client-auditing output when an unhardened OpenSSH v7.2 client connects: ![client_screenshot](https://user-images.githubusercontent.com/2982011/68867998-b946c100-06c4-11ea-975f-1f47e4178a74.png) ### Hardening Guides Guides to harden server & client configuration can be found here: [https://www.ssh-audit.com/hardening_guides.html](https://www.ssh-audit.com/hardening_guides.html) ### Pre-Built Packages Pre-built packages are available for Windows (see the releases page), on PyPI, Snap, and Homebrew. To install from PyPI: ``` $ pip3 install ssh-audit ``` To install the Snap package: ``` $ snap install ssh-audit ``` To install on Homebrew: ``` $ brew install ssh-audit ``` To install from Dockerhub: ``` $ docker pull positronsecurity/ssh-audit ``` (Then run with: `docker run -it -p 2222:2222 positronsecurity/ssh-audit 10.1.1.1`) ### Web Front-End For convenience, a web front-end on top of the command-line tool is available at [https://www.ssh-audit.com/](https://www.ssh-audit.com/). ## ChangeLog ### v2.4.0-dev (???) - Added version check for OpenSSH user enumeration (CVE-2018-15473). - Fixed crash when receiving unexpected response during host key test. ### v2.3.1 (2020-10-28) - Now parses public key sizes for `rsa-sha2-256-cert-v01@openssh.com` and `rsa-sha2-512-cert-v01@openssh.com` host key types. - Flag `ssh-rsa-cert-v01@openssh.com` as a failure due to SHA-1 hash. - Fixed bug in recommendation output which suppressed some algorithms inappropriately. - Built-in policies now include CA key requirements (if certificates are in use). - Lookup function (`--lookup`) now performs case-insensitive lookups of similar algorithms; credit [Adam Russell](https://github.com/thecliguy). - Migrated pre-made policies from external files to internal database. - Split single 3,500 line script into many files (by class). - Added setup.py support; credit [Ganden Schaffner](https://github.com/gschaffner). - Added 1 new cipher: `des-cbc@ssh.com`. ### v2.3.0 (2020-09-27) - Added new policy auditing functionality to test adherence to a hardening guide/standard configuration (see `-L`/`--list-policies`, `-M`/`--make-policy` and `-P`/`--policy`). For an in-depth tutorial, see . - Created new man page (see `ssh-audit.1` file). - 1024-bit moduli upgraded from warnings to failures. - Many Python 2 code clean-ups, testing framework improvements, pylint & flake8 fixes, and mypy type comments; credit [Jürgen Gmach](https://github.com/jugmac00). - Added feature to look up algorithms in internal database (see `--lookup`); credit [Adam Russell](https://github.com/thecliguy). - Suppress recommendation of token host key types. - Added check for use-after-free vulnerability in PuTTY v0.73. - Added 11 new host key types: `ssh-rsa1`, `ssh-dss-sha256@ssh.com`, `ssh-gost2001`, `ssh-gost2012-256`, `ssh-gost2012-512`, `spki-sign-rsa`, `ssh-ed448`, `x509v3-ecdsa-sha2-nistp256`, `x509v3-ecdsa-sha2-nistp384`, `x509v3-ecdsa-sha2-nistp521`, `x509v3-rsa2048-sha256`. - Added 8 new key exchanges: `diffie-hellman-group1-sha256`, `kexAlgoCurve25519SHA256`, `Curve25519SHA256`, `gss-group14-sha256-`, `gss-group15-sha512-`, `gss-group16-sha512-`, `gss-nistp256-sha256-`, `gss-curve25519-sha256-`. - Added 5 new ciphers: `blowfish`, `AEAD_AES_128_GCM`, `AEAD_AES_256_GCM`, `crypticore128@ssh.com`, `seed-cbc@ssh.com`. - Added 3 new MACs: `chacha20-poly1305@openssh.com`, `hmac-sha3-224`, `crypticore-mac@ssh.com`. ### v2.2.0 (2020-03-11) - Marked host key type `ssh-rsa` as weak due to [practical SHA-1 collisions](https://eprint.iacr.org/2020/014.pdf). - Added Windows builds. - Added 10 new host key types: `ecdsa-sha2-1.3.132.0.10`, `x509v3-sign-dss`, `x509v3-sign-rsa`, `x509v3-sign-rsa-sha256@ssh.com`, `x509v3-ssh-dss`, `x509v3-ssh-rsa`, `sk-ecdsa-sha2-nistp256-cert-v01@openssh.com`, `sk-ecdsa-sha2-nistp256@openssh.com`, `sk-ssh-ed25519-cert-v01@openssh.com`, and `sk-ssh-ed25519@openssh.com`. - Added 18 new key exchanges: `diffie-hellman-group14-sha256@ssh.com`, `diffie-hellman-group15-sha256@ssh.com`, `diffie-hellman-group15-sha384@ssh.com`, `diffie-hellman-group16-sha384@ssh.com`, `diffie-hellman-group16-sha512@ssh.com`, `diffie-hellman-group18-sha512@ssh.com`, `ecdh-sha2-curve25519`, `ecdh-sha2-nistb233`, `ecdh-sha2-nistb409`, `ecdh-sha2-nistk163`, `ecdh-sha2-nistk233`, `ecdh-sha2-nistk283`, `ecdh-sha2-nistk409`, `ecdh-sha2-nistp192`, `ecdh-sha2-nistp224`, `ecdh-sha2-nistt571`, `gss-gex-sha1-`, and `gss-group1-sha1-`. - Added 9 new ciphers: `camellia128-cbc`, `camellia128-ctr`, `camellia192-cbc`, `camellia192-ctr`, `camellia256-cbc`, `camellia256-ctr`, `aes128-gcm`, `aes256-gcm`, and `chacha20-poly1305`. - Added 2 new MACs: `aes128-gcm` and `aes256-gcm`. ### v2.1.1 (2019-11-26) - Added 2 new host key types: `rsa-sha2-256-cert-v01@openssh.com`, `rsa-sha2-512-cert-v01@openssh.com`. - Added 2 new ciphers: `des`, `3des`. - Added 3 new PuTTY vulnerabilities. - During client testing, client IP address is now listed in output. ### v2.1.0 (2019-11-14) - Added client software auditing functionality (see `-c` / `--client-audit` option). - Added JSON output option (see `-j` / `--json` option; credit [Andreas Jaggi](https://github.com/x-way)). - Fixed crash while scanning Solaris Sun_SSH. - Added 9 new key exchanges: `gss-group1-sha1-toWM5Slw5Ew8Mqkay+al2g==`, `gss-gex-sha1-toWM5Slw5Ew8Mqkay+al2g==`, `gss-group14-sha1-`, `gss-group14-sha1-toWM5Slw5Ew8Mqkay+al2g==`, `gss-group14-sha256-toWM5Slw5Ew8Mqkay+al2g==`, `gss-group15-sha512-toWM5Slw5Ew8Mqkay+al2g==`, `diffie-hellman-group15-sha256`, `ecdh-sha2-1.3.132.0.10`, `curve448-sha512`. - Added 1 new host key type: `ecdsa-sha2-1.3.132.0.10`. - Added 4 new ciphers: `idea-cbc`, `serpent128-cbc`, `serpent192-cbc`, `serpent256-cbc`. - Added 6 new MACs: `hmac-sha2-256-96-etm@openssh.com`, `hmac-sha2-512-96-etm@openssh.com`, `hmac-ripemd`, `hmac-sha256-96@ssh.com`, `umac-32@openssh.com`, `umac-96@openssh.com`. ### v2.0.0 (2019-08-29) - Forked from https://github.com/arthepsy/ssh-audit (development was stalled, and developer went MIA). - Added RSA host key length test. - Added RSA certificate key length test. - Added Diffie-Hellman modulus size test. - Now outputs host key fingerprints for RSA and ED25519. - Added 5 new key exchanges: `sntrup4591761x25519-sha512@tinyssh.org`, `diffie-hellman-group-exchange-sha256@ssh.com`, `diffie-hellman-group-exchange-sha512@ssh.com`, `diffie-hellman-group16-sha256`, `diffie-hellman-group17-sha512`. - Added 3 new encryption algorithms: `des-cbc-ssh1`, `blowfish-ctr`, `twofish-ctr`. - Added 10 new MACs: `hmac-sha2-56`, `hmac-sha2-224`, `hmac-sha2-384`, `hmac-sha3-256`, `hmac-sha3-384`, `hmac-sha3-512`, `hmac-sha256`, `hmac-sha256@ssh.com`, `hmac-sha512`, `hmac-512@ssh.com`. - Added command line argument (`-t` / `--timeout`) for connection & reading timeouts. - Updated CVEs for libssh & Dropbear. ### v1.7.0 (2016-10-26) - implement options to allow specify IPv4/IPv6 usage and order of precedence - implement option to specify remote port (old behavior kept for compatibility) - add colors support for Microsoft Windows via optional colorama dependency - fix encoding and decoding issues, add tests, do not crash on encoding errors - use mypy-lang for static type checking and verify all code ### v1.6.0 (2016-10-14) - implement algorithm recommendations section (based on recognized software) - implement full libssh support (version history, algorithms, security, etc) - fix SSH-1.99 banner recognition and version comparison functionality - do not output empty algorithms (happens for misconfigured servers) - make consistent output for Python 3.x versions - add a lot more tests (conf, banner, software, SSH1/SSH2, output, etc) - use Travis CI to test for multiple Python versions (2.6-3.5, pypy, pypy3) ### v1.5.0 (2016-09-20) - create security section for related security information - match and output assigned CVE list and security issues for Dropbear SSH - implement full SSH1 support with fingerprint information - automatically fallback to SSH1 on protocol mismatch - add new options to force SSH1 or SSH2 (both allowed by default) - parse banner information and convert it to specific software and OS version - do not use padding in batch mode - several fixes (Cisco sshd, rare hangs, error handling, etc) ### v1.0.20160902 - implement batch output option - implement minimum output level option - fix compatibility with Python 2.6 ### v1.0.20160812 - implement SSH version compatibility feature - fix wrong mac algorithm warning - fix Dropbear SSH version typo - parse pre-banner header - better errors handling ### v1.0.20160803 - use OpenSSH 7.3 banner - add new key-exchange algorithms ### v1.0.20160207 - use OpenSSH 7.2 banner - additional warnings for OpenSSH 7.2 - fix OpenSSH 7.0 failure messages - add rijndael-cbc failure message from OpenSSH 6.7 ### v1.0.20160105 - multiple additional warnings - support for none algorithm - better compression handling - ensure reading enough data (fixes few Linux SSH) ### v1.0.20151230 - Dropbear SSH support ### v1.0.20151223 - initial version