From 6f46fb81318b943593b7b5c863b13bf5cb2afce0 Mon Sep 17 00:00:00 2001
From: Kosiorkosa47 <mkosiorek121@gmail.com>
Date: Thu, 21 May 2026 15:23:27 +0000
Subject: [PATCH] Tighten UNSAFE_PATH_PATTERN against encoded path-traversal terminators (#49000)
---
src/main/java/org/keycloak/protocol/cas/utils/RedirectUtils.java | 73 ++++++++++++++++++++++++++++--------
1 files changed, 56 insertions(+), 17 deletions(-)
diff --git a/src/main/java/org/keycloak/protocol/cas/utils/RedirectUtils.java b/src/main/java/org/keycloak/protocol/cas/utils/RedirectUtils.java
index d744f65..51432b1 100644
--- a/src/main/java/org/keycloak/protocol/cas/utils/RedirectUtils.java
+++ b/src/main/java/org/keycloak/protocol/cas/utils/RedirectUtils.java
@@ -150,12 +150,16 @@
}
// any access to parent folder /../ is unsafe with or without encoding
+ // <sep> = / | %2F | %5C | \
+ // <dots> = "..", including %2E and %252E (double-encoded) variants
+ // <terminator> = / | %2F | %5C | \ | ; | %3B | %09 | %0A | %0D | %00 | end-of-input
private final static Pattern UNSAFE_PATH_PATTERN = Pattern.compile(
- "(/|%2[fF]|%5[cC]|\\\\)(%2[eE]|\\.){2}(/|%2[fF]|%5[cC]|\\\\|;)|(/|%2[fF]|%5[cC]|\\\\)(%2[eE]|\\.){2}$");
+ "(/|%2[fF]|%5[cC]|\\\\)(%2[eE]|%252[eE]|\\.){2}(/|%2[fF]|%5[cC]|\\\\|;|%3[bB]|%09|%0[aAdD]|%00|$)");
private static boolean areWildcardsAllowed(URI redirectUri) {
- // wildcars are only allowed if no user-info and no unsafe pattern in path
+ // wildcars are only allowed if no user-info and no unparsed authority and no unsafe pattern in path
return redirectUri.getRawUserInfo() == null
+ && !(redirectUri.getRawAuthority() != null && redirectUri.getRawUserInfo() == null && redirectUri.getHost() == null && redirectUri.getPort() == -1)
&& (redirectUri.getRawPath() == null || !UNSAFE_PATH_PATTERN.matcher(redirectUri.getRawPath()).find());
}
@@ -180,22 +184,57 @@
if ("*".equals(validRedirect)) {
// the valid redirect * is a full wildcard for http(s) even if the redirect URI does not allow wildcards
return validRedirect;
- } else if (validRedirect.endsWith("*") && !validRedirect.contains("?") && allowWildcards) {
- // strip off the query or fragment components - we don't check them when wildcards are effective
- int idx = redirect.indexOf('?');
- if (idx == -1) {
- idx = redirect.indexOf('#');
+ } else {
+ String validRedirectWildcard = allowWildcards ? checkValidRedirectWildcard(validRedirect) : null;
+ if (validRedirectWildcard != null) {
+ // strip off the query or fragment components - we don't check them when wildcards are effective
+ int idx = redirect.indexOf('?');
+ if (idx == -1) {
+ idx = redirect.indexOf('#');
+ }
+ String r = idx == -1 ? redirect : redirect.substring(0, idx);
+ // strip off *
+ int length = validRedirectWildcard.length() - 1;
+ validRedirectWildcard = validRedirectWildcard.substring(0, length);
+ if (r.startsWith(validRedirectWildcard)) {
+ return validRedirectWildcard;
+ }
+ // strip off trailing '/'
+ if (length - 1 > 0 && validRedirectWildcard.charAt(length - 1) == '/') {
+ length--;
+ }
+ validRedirectWildcard = validRedirectWildcard.substring(0, length);
+ if (validRedirectWildcard.equals(r)) {
+ return validRedirectWildcard;
+ }
+ } else if (validRedirect.equals(redirect)) {
+ return validRedirect;
}
- String r = idx == -1 ? redirect : redirect.substring(0, idx);
- // strip off *
- int length = validRedirect.length() - 1;
- validRedirect = validRedirect.substring(0, length);
- if (r.startsWith(validRedirect)) return validRedirect;
- // strip off trailing '/'
- if (length - 1 > 0 && validRedirect.charAt(length - 1) == '/') length--;
- validRedirect = validRedirect.substring(0, length);
- if (validRedirect.equals(r)) return validRedirect;
- } else if (validRedirect.equals(redirect)) return validRedirect;
+ }
+ }
+ return null;
+ }
+
+ private static String checkValidRedirectWildcard(String validRedirect) {
+ if (!validRedirect.endsWith("*") || validRedirect.contains("?") || validRedirect.contains("#")) {
+ return null; // no wildcard as before
+ }
+ KeycloakUriBuilder uriBuilder = KeycloakUriBuilder.fromUri(validRedirect, false);
+ if (uriBuilder.getPath() != null) {
+ return validRedirect; // wildcard valid on path
+ }
+ if (uriBuilder.getAuthority() != null) {
+ if (uriBuilder.getAuthority().equals("*") || uriBuilder.getAuthority().endsWith(":*")) {
+ return validRedirect; // on authority just full wildcard or on port
+ } else {
+ // treat the wildcard after the authority
+ validRedirect = validRedirect.substring(0, validRedirect.length() - 1);
+ validRedirect = validRedirect + "/*";
+ return validRedirect;
+ }
+ }
+ if (uriBuilder.getSsp() != null) {
+ return validRedirect; // wildcard valid on SSP
}
return null;
}
--
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