1 files changed, 33 insertions, 0 deletions
diff --git a/main/expat/CVE-2022-25236.patch b/main/expat/CVE-2022-25236.patch
new file mode 100644
index 00000000000..ad91fc195fa
--- /dev/null
+++ b/main/expat/CVE-2022-25236.patch
@@ -0,0 +1,33 @@
+Patch-Source: https://github.com/libexpat/libexpat/commit/a2fe525e660badd64b6c557c2b1ec26ddc07f6e4
+From a2fe525e660badd64b6c557c2b1ec26ddc07f6e4 Mon Sep 17 00:00:00 2001
+From: Sebastian Pipping <sebastian@pipping.org>
+Date: Sat, 12 Feb 2022 01:09:29 +0100
+Subject: [PATCH] lib: Protect against malicious namespace declarations
+ (CVE-2022-25236)
+
+---
+ expat/lib/xmlparse.c | 11 +++++++++++
+ 1 file changed, 11 insertions(+)
+
+diff --git a/expat/lib/xmlparse.c b/expat/lib/xmlparse.c
+index c768f856..a3aef88c 100644
+--- a/lib/xmlparse.c
++++ b/lib/xmlparse.c
+@@ -3754,6 +3754,17 @@ addBinding(XML_Parser parser, PREFIX *prefix, const ATTRIBUTE_ID *attId,
+     if (! mustBeXML && isXMLNS
+         && (len > xmlnsLen || uri[len] != xmlnsNamespace[len]))
+       isXMLNS = XML_FALSE;
++
++    // NOTE: While Expat does not validate namespace URIs against RFC 3986,
++    //       we have to at least make sure that the XML processor on top of
++    //       Expat (that is splitting tag names by namespace separator into
++    //       2- or 3-tuples (uri-local or uri-local-prefix)) cannot be confused
++    //       by an attacker putting additional namespace separator characters
++    //       into namespace declarations.  That would be ambiguous and not to
++    //       be expected.
++    if (parser->m_ns && (uri[len] == parser->m_namespaceSeparator)) {
++      return XML_ERROR_SYNTAX;
++    }
+   }
+   isXML = isXML && len == xmlLen;
+   isXMLNS = isXMLNS && len == xmlnsLen;