From f1d84cea358fbeb31753834c3cd816a2225ff292 Mon Sep 17 00:00:00 2001
From: Will Sowerbutts <will@sowerbutts.com>
Date: Thu, 11 Jul 2024 13:38:48 +0100
Subject: [PATCH] Remove unexpected control codes from ICS files

---
 radicale/item/__init__.py | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/radicale/item/__init__.py b/radicale/item/__init__.py
index c5a32690..c10824a6 100644
--- a/radicale/item/__init__.py
+++ b/radicale/item/__init__.py
@@ -49,6 +49,12 @@ def read_components(s: str) -> List[vobject.base.Component]:
     s = re.sub(r"^(PHOTO(?:;[^:\r\n]*)?;ENCODING=b(?:;[^:\r\n]*)?:)"
                r"data:[^;,\r\n]*;base64,", r"\1", s,
                flags=re.MULTILINE | re.IGNORECASE)
+    # Workaround for bug with malformed ICS files containing control codes
+    # Filter out all control codes except those we expect to find:
+    #  * 0x09 Horizontal Tab
+    #  * 0x0A Line Feed
+    #  * 0x0D Carriage Return
+    s = re.sub(r'[\x00-\x08\x0B\x0C\x0E-\x1F]', '', s)
     return list(vobject.readComponents(s, allowQP=True))