## https://sploitus.com/exploit?id=KITPLOIT:5314135747123043538
# ssh-audit
  
   
**ssh-audit** is a tool for ssh server & client configuration auditing.
jtesta/ssh-audit (v2.0+) is the updated and maintained version of ssh-audit forked from arthepsy/ssh-audit (v1.x) due to inactivity.
* Features
* Usage
* Screenshots
* Server Standard Audit Example
* Server Policy Audit Example
* Client Standard Audit Example
* Hardening Guides
* Pre-Built Packages
* Web Front-End
* ChangeLog
## Features
* analyze SSH both server and 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 security information (available since, removed/disabled, unsafe/weak/legacy, etc);
* output algorithm recommendations (append or remove based on recognized software version);
* 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;
* supports Python 3.10 - 3.14;
* no dependencies
## Usage
root@kitploit:~
usage: ssh-audit.py [-h] [-4] [-6] [-b] [-c] [-d]
[-g <min1:pref1:max1[,min2:pref2:max2,...]> / <x-y[:step]>]
[-j] [-l {info,warn,fail}] [-L] [-M custom_policy.txt]
[-m] [-n] [-P "Built-In Policy Name" / custom_policy.txt]
[-p N] [-T targets.txt] [-t N] [-v]
[--conn-rate-test N[:max_rate]] [--dheat N[:kex[:e_len]]]
[--get-hardening-guide platform] [--list-hardening-guides]
[--lookup alg1[,alg2,...]] [--skip-rate-test]
[--socks5 host:port] [--threads N]
[host]
# ssh-audit.py v3.4.1-dev, https://github.com/jtesta/ssh-audit
positional arguments:
host target hostname or IPv4/IPv6 address
optional arguments:
-h, --help show this help message and exit
-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)
-d, --debug enable debugging output
-g <min1:pref1:max1[,min2:pref2:max2,...]> / <x-y[:step]>, --gex-test <min1:pref1:max1[,min2:pref2:max2,...]> / <x-y[:step]>
conducts a very customized Diffie-Hellman GEX modulus
size test. Tests an array of minimum, preferred, and
maximum values, or a range of values with an optional
incremental step amount
-j, --json enable JSON output (use -jj to enable indentation for
better readability)
-l {info,warn,fail}, --level {info,warn,fail}
minimum output level (default: info)
-L, --list-policies list all the official, built-in policies. Combine with
-v to view policy change logs
-M custom_policy.txt, --make-policy custom_policy.txt
creates a policy based on the target server (i.e.: the
target server has the ideal configuration that other
servers should adhere to), and stores it in the file
path specified
-m, --manual print the man page (Docker, PyPI, Snap, and Windows
builds only)
-n, --no-colors disable colors (automatic when the NO_COLOR
environment variable is set)
-P "Built-In Policy Name" / custom_policy.txt, --policy "Built-In Policy Name" / custom_policy.txt
run a policy test using the specified policy (use -L
to see built-in policies, or specify filesystem path
to custom policy created by -M)
-p N, --port N the TCP port to connect to (or to listen on when -c is
used)
-T targets.txt, --targets targets.txt
a file containing a list of target hosts (one per
line, format 'HOST[:PORT]'; for UNIX socket servers,
use 'unix:///path/socket'). Use -p/--port to set the
default port for all hosts. Use --threads to control
concurrent scans
-t N, --timeout N timeout (in seconds) for connection and reading
(default: 5)
-v, --verbose enable verbose output
--conn-rate-test N[:max_rate]
perform a connection rate test (useful for collecting
metrics related to susceptibility of the DHEat vuln).
Testing is conducted with N concurrent sockets with an
optional maximum rate of connections per second
--dheat N[:kex[:e_len]]
continuously perform the DHEat DoS attack
(CVE-2002-20001) against the target using N concurrent
sockets. Optionally, a specific key exchange algorithm
can be specified instead of allowing it to be
automatically chosen. Additionally, a small length of
the fake e value sent to the server can be chosen for
a more efficient attack (such as 4).
--get-hardening-guide platform
retrieves the hardening guide for the specified
platform name (use --list-hardening-guides to see list
of available guides).
--list-hardening-guides
list all official, built-in hardening guides for
common systems. Their full names can then be passed to
--get-hardening-guide. Add -v to this option to view
hardening guide change logs and prior versions.
--lookup alg1[,alg2,...]
looks up an algorithm(s) without connecting to a
server.
--skip-rate-test skip the connection rate test during standard audits
(used to safely infer whether the DHEat attack is
viable)
--socks5 host:port connect via a SOCKS5 proxy (implies --skip-rate-test)
--threads N number of threads to use when scanning multiple
targets (-T/--targets) (default: 32)
* 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:
root@kitploit:~
ssh-audit localhost
ssh-audit 127.0.0.1
ssh-audit 127.0.0.1:222
ssh-audit ::1
ssh-audit [::1]:222
ssh-audit unix:///run/ssh-unix-local/socket
To run a standard audit against many servers (place targets into servers.txt, one on each line in the format of `HOST[:PORT]`):
root@kitploit:~
ssh-audit -T servers.txt
To audit a client configuration (listens on port 2222/tcp by default; connect using `ssh -p 2222 anything@localhost`):
root@kitploit:~
ssh-audit -c
To audit a client configuration, with a listener on port 4567/tcp:
root@kitploit:~
ssh-audit -c -p 4567
To list all official built-in policies (hint: use resulting policy names with `-P`/`--policy`):
root@kitploit:~
ssh-audit -L
To run a policy audit against a server:
root@kitploit:~
ssh-audit -P ["policy name" | path/to/server_policy.txt] targetserver
To run a policy audit against a client:
root@kitploit:~
ssh-audit -c -P ["policy name" | path/to/client_policy.txt]
To run a policy audit against many servers:
root@kitploit:~
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):
root@kitploit:~
ssh-audit -M new_policy.txt targetserver
To run the DHEat CPU exhaustion DoS attack (CVE-2002-20001) against a target using 10 concurrent sockets:
root@kitploit:~
ssh-audit --dheat=10 targetserver
To run the DHEat attack using the `diffie-hellman-group-exchange-sha256` key exchange algorithm:
root@kitploit:~
ssh-audit --dheat=10:diffie-hellman-group-exchange-sha256 targetserver
To run the DHEat attack using the `diffie-hellman-group-exchange-sha256` key exchange algorithm along with very small but non-standard packet lengths (this may result in the same CPU exhaustion, but with many less bytes per second being sent):
root@kitploit:~
ssh-audit --dheat=10:diffie-hellman-group-exchange-sha256:4 targetserver
## Screenshots
### Server Standard Audit Example
Below is a screen shot of the standard server-auditing output when connecting to an unhardened OpenSSH v5.3 service: 
### 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 (hint: use `-L`/`--list-policies` to see names of built-in policies to use with `-P`/`--policy`): 
After applying the steps in the hardening guide (see below), the output changes to the following: 
### Client Standard Audit Example
Below is a screen shot of the client-auditing output when an unhardened OpenSSH v7.2 client connects: 
## Hardening Guides
Guides to harden server & client configuration are built into the tool (see `--list-hardening-guides` and `--get-hardening-guide` options). Additionally, they are also available online at: https://www.ssh-audit.com/hardening_guides.html
## Pre-Built Packages
Pre-built packages are available for Windows (see the Releases page), PyPI, Snap, and Docker:
To install from PyPI:
root@kitploit:~
$ pip3 install ssh-audit
To install the Snap package:
root@kitploit:~
$ snap install ssh-audit
To install from Dockerhub:
root@kitploit:~
$ docker pull docker.io/positronsecurity/ssh-audit
(Then run with: `docker run -it --rm -p 2222:2222 docker.io/positronsecurity/ssh-audit 10.1.1.1`)
The status of various other platform packages can be found below (via Repology):
## Web Front-End
For convenience, a web front-end on top of the command-line tool is available at https://www.ssh-audit.com/.
## ChangeLog
### v3.9.1-dev
* Fixed a perhaps rare crash when performing connection rate tests during standard audits.
### v3.9.0 (2026-07-04)
* BIG THANKS to realmiwi for being the project's _very first sponsor!!_
* Added support for Python 3.14.
* Dropped support for Python 3.8, as it reached end-of-life in October 2024.
* Dropped support for Python 3.9, as it reached end-of-life in October 2025.
* Added warning to all key exchanges that do not include protections against quantum attacks due to the Harvest Now, Decrypt Later strategy (see https://en.wikipedia.org/wiki/Harvest_now,_decrypt_later).
* Removed SSHv1 support (rationale is documented in: https://github.com/jtesta/ssh-audit/issues/298).
* Added hardening guides (see `--list-hardening-guides` and `--get-hardening-guide`). Previously, they were only available at https://ssh-audit.com/hardening_guides.html, but now they are built-in for convenience; partial credit oam7575.
* Added `allow_hostkey_subset_and_reordering` policy option to allow targets to have a more stringent list of host keys and/or a different ordering of them.
* Migrated from deprecated `getopt` module to `argparse`; partial credit oam7575.
* When running against multiple hosts, now prints each target host regardless of output level.
* Batch mode (`-b`) no longer automatically enables verbose mode, due to sometimes confusing results; users can still explicitly enable verbose mode using the flag.
### v3.3.0 (2024-10-15)
* Added Python 3.13 support.
* Added built-in policies for Ubuntu 24.04 LTS server & client, OpenSSH 9.8, and OpenSSH 9.9.
* Added IPv6 support for DHEat and connection rate tests.
* Added TCP port information to JSON policy scan results; credit Fabian Malte Kopp.
* Added LANcom LCOS server recognition and Ed448 key extraction; credit Daniel Lenski.
* Now reports ECDSA and DSS fingerprints when in verbose mode; partial credit Daniel Lenski.
* Removed CVE information based on server/client version numbers, as this was wildly inaccurate (see this thread for the full discussion, as well as the results of the community vote on this matter).
* Fixed crash when running with `-P` and `-T` options simultaneously.
* Fixed host key tests from only reporting a key type at most once despite multiple hosts supporting it; credit Daniel Lenski.
* Fixed DHEat connection rate testing on MacOS X and BSD platforms; credit Drew Noel and Michael Osipov.
* Fixed invalid JSON output when a socket error occurs while performing a client audit.
* Fixed `--conn-rate-test` feature on Windows.
* When scanning multiple targets (using `-T`/`--targets`), the `-p`/`--port` option will now be used as the default port (set to 22 if / is not given). Hosts specified in the file can override this default with an explicit port number (i.e.: "host1:1234"). For example, when using , all hosts in that do not explicitly include a port number will default to 222; when using (without ), all hosts will use a default of 22.
### v3.2.0 (2024-04-22)
* Added implementation of the DHEat denial-of-service attack (see `--dheat` option; CVE-2002-20001).
* Expanded filter of CBC ciphers to flag for the Terrapin vulnerability. It now includes more rarely found ciphers.
* Fixed parsing of `ecdsa-sha2-nistp*` CA signatures on host keys. Additionally, they are now flagged as potentially back-doored, just as standard host keys are.
* Gracefully handle rare exceptions (i.e.: crashes) while performing GEX tests.
* The built-in man page (`-m`, `--manual`) is now available on Docker, PyPI, and Snap builds, in addition to the Windows build.
* Snap builds are now architecture-independent.
* Changed Docker base image from `python:3-slim` to `python:3-alpine`, resulting in a 59% reduction in image size; credit Daniel Thamdrup.
* Added built-in policies for Amazon Linux 2023, Debian 12, OpenSSH 9.7, and Rocky Linux 9.
* Built-in policies now include a change log (use `-L -v` to view them).
* Custom policies now support the `allow_algorithm_subset_and_reordering` directive to allow targets to pass with a subset and/or re-ordered list of host keys, kex, ciphers, and MACs. This allows for the creation of a baseline policy where targets can optionally implement stricter controls; partial credit .
### v3.1.0 (2023-12-20)
* Added test for the Terrapin message prefix truncation vulnerability (CVE-2023-48795).
* Dropped support for Python 3.7 (EOL was reached in June 2023).
* Added Python 3.12 support.
* In server policies, reduced expected DH modulus sizes from 4096 to 3072 to match the online hardening guides (note that 3072-bit moduli provide the equivalent of 128-bit symmetric security).
* In Ubuntu 22.04 client policy, moved host key types `some-email@example.com` and `ssh-ed25519` to the end of all certificate types.
* Updated Ubuntu Server & Client policies for 20.04 and 22.04 to account for key exchange list changes due to Terrapin vulnerability patches.
* Re-organized option host key types for OpenSSH 9.2 server policy to correspond with updated Debian 12 hardening guide.
* Added built-in policies for OpenSSH 9.5 and 9.6.
* Added an `additional_notes` field to the JSON output.
### v3.0.0 (2023-09-07)
* Results from concurrent scans against multiple hosts are no longer improperly combined; bug discovered by Adam Russell.
* Hostname resolution failure no longer causes scans against multiple hosts to terminate unexpectedly; credit Dani Cuesta.
* Algorithm recommendations resulting from warnings are now printed in yellow instead of red; credit Adam Russell.
* Added failure, warning, and info notes to JSON output (note that this results in a breaking change to the banner protocol, "enc", and "mac" fields); credit Bareq Al-Azzawi.
* Docker Makefile now creates multi-arch builds for amd64, arm64, and armv7; credit Sebastian Cohnen.
* Fixed crash during GEX tests.
* Refined GEX testing against OpenSSH servers: when the fallback mechanism is suspected of being triggered, perform an additional test to obtain more accurate results.
* The color of all notes will be printed in green when the related algorithm is rated good.
* Prioritized host key certificate algorithms for Ubuntu 22.04 LTS client policy.
* Marked all NIST K-, B-, and T-curves as unproven since they are so rarely used.
* Added built-in policy for OpenSSH 9.4.
* Added 12 new host keys: `ecdsa-sha2-curve25519`, `ecdsa-sha2-nistb233`, `ecdsa-sha2-nistb409`, `ecdsa-sha2-nistk163`, `ecdsa-sha2-nistk233`, `ecdsa-sha2-nistk283`, , , , , , .
### v2.9.0 (2023-04-29)
* Dropped support for Python 3.6, as it reached EOL at the end of 2021.
* Added Ubuntu Server & Client 22.04 hardening policies.
* Removed experimental warning tag from `some-email@example.com`.
* Updated CVE database; credit Alexandre Zanni.
* Added `-g` and `--gex-test` for granular GEX modulus size tests; credit Adam Russell.
* Snap packages now print more user-friendly error messages when permission errors are encountered.
* JSON 'target' field now always includes port number; credit tomatohater1337.
* JSON output now includes recommendations and CVE data.
* Mixed host key/CA key types (i.e.: RSA host keys signed with ED25519 CAs, etc.) are now properly handled.
* Warnings are now printed for 2048-bit moduli; partial credit Adam Russell.
* SHA-1 algorithms now cause failures.
* CBC mode ciphers are now warnings instead of failures.
* Generic failure/warning messages replaced with more specific reasons (i.e.: 'using weak cipher' => 'using broken RC4 cipher').
* Updated built-in policies to include missing host key size information.
* Added built-in policies for OpenSSH 8.8, 8.9, 9.0, 9.1, 9.2, and 9.3.
* Added 33 new host keys: `some-email@example.com`, `some-email@example.com`, `some-email@example.com`, `some-email@example.com`, , , , , , , , , , , , , , , , , , , , , , , , , , , , , .
### v2.5.0 (2021-08-26)
* Fixed crash when running host key tests.
* Handles server connection failures more gracefully.
* Now prints JSON with indents when `-jj` is used (useful for debugging).
* Added MD5 fingerprints to verbose output.
* Added `-d`/`--debug` option for getting debugging output; credit Adam Russell.
* Updated JSON output to include MD5 fingerprints. Note that this results in a breaking change in the 'fingerprints' dictionary format.
* Updated OpenSSH 8.1 (and earlier) policies to include `rsa-sha2-512` and `rsa-sha2-256`.
* Added OpenSSH v8.6 & v8.7 policies.
* Added 3 new key exchanges: `gss-gex-sha1-eipGX3TCiQSrx573bT1o1Q==`, `gss-group1-sha1-eipGX3TCiQSrx573bT1o1Q==`, and `gss-group14-sha1-eipGX3TCiQSrx573bT1o1Q==`.
* Added 3 new MACs: `hmac-ripemd160-96`, `AEAD_AES_128_GCM`, and `AEAD_AES_256_GCM`.
### v2.4.0 (2021-02-23)
* Added multi-threaded scanning support.
* Added built-in Windows manual page (see `-m`/`--manual`); credit Adam Russell.
* Added version check for OpenSSH user enumeration (CVE-2018-15473).
* Added deprecation note to host key types based on SHA-1.
* Added extra warnings for SSHv1.
* Added built-in hardened OpenSSH v8.5 policy.
* Upgraded warnings to failures for host key types based on SHA-1.
* Fixed crash when receiving unexpected response during host key test.
* Fixed hang against older Cisco devices during host key test & gex test.
* Fixed improper termination while scanning multiple targets when one target returns an error.
* Dropped support for Python 3.5 (which reached EOL in Sept. 2020).
* Added 1 new key exchange: `some-email@example.com`.
### v2.3.1 (2020-10-28)
* Now parses public key sizes for `some-email@example.com` and `some-email@example.com` host key types.
* Flag `some-email@example.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.
* 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.
* Added 1 new cipher: `some-email@example.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 https://www.positronsecurity.com/blog/2020-09-27-ssh-policy-configuration-checks-with-ssh-audit/.
* 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.
* Added feature to look up algorithms in internal database (see `--lookup`); credit Adam Russell.
* 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`, `some-email@example.com`, , , , , , , , , .
### v2.2.0 (2020-03-11)
* Marked host key type `ssh-rsa` as weak due to practical SHA-1 collisions.
* Added Windows builds.
* Added 10 new host key types: `ecdsa-sha2-1.3.132.0.10`, `x509v3-sign-dss`, `x509v3-sign-rsa`, `some-email@example.com`, `x509v3-ssh-dss`, `x509v3-ssh-rsa`, `some-email@example.com`, `some-email@example.com`, `some-email@example.com`, and `some-email@example.com`.
* Added 18 new key exchanges: `some-email@example.com`, , , , , , , , , , , , , , , , , and .
### v2.1.1 (2019-11-26)
* Added 2 new host key types: `some-email@example.com`, `some-email@example.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).
* 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`, .
### 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: `some-email@example.com`, `some-email@example.com`, `some-email@example.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`, , , , , , , .
### 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