Suggested fix for PHP bug #81420

.patch

From 4db35baad4657ababb20e95c3e3c076953e0c261 Mon Sep 17 00:00:00 2001
From: "Christoph M. Becker" <cmbecker69@gmx.de>
Date: Mon, 6 Sep 2021 17:42:46 +0200
Subject: [PATCH] Fix #81420: ZipArchive::extractTo extracts outside of
 destination

We need to properly detect and handle absolute paths in a portable way.
---
 ext/zip/php_zip.c           |   4 ++--
 ext/zip/tests/bug81420.phpt |  24 ++++++++++++++++++++++++
 ext/zip/tests/bug81420.zip  | Bin 0 -> 218 bytes
 3 files changed, 26 insertions(+), 2 deletions(-)
 create mode 100644 ext/zip/tests/bug81420.phpt
 create mode 100644 ext/zip/tests/bug81420.zip

diff --git a/ext/zip/php_zip.c b/ext/zip/php_zip.c
index 2a2577de22..57aa4df34f 100644
--- a/ext/zip/php_zip.c
+++ b/ext/zip/php_zip.c
@@ -102,8 +102,8 @@ static char * php_zip_make_relative_path(char *path, size_t path_len) /* {{{ */
 		return NULL;
 	}
 
-	if (IS_SLASH(path[0])) {
-		return path + 1;
+	if (IS_ABSOLUTE_PATH(path, path_len)) {
+		return path + COPY_WHEN_ABSOLUTE(path) + 1;
 	}
 
 	i = path_len;
diff --git a/ext/zip/tests/bug81420.phpt b/ext/zip/tests/bug81420.phpt
new file mode 100644
index 0000000000..9eec0ee7e9
--- /dev/null
+++ b/ext/zip/tests/bug81420.phpt
@@ -0,0 +1,24 @@
+--TEST--
+Bug #81420 (ZipArchive::extractTo extracts outside of destination)
+--SKIPIF--
+<?php
+if (!extension_loaded("zip")) die("skip zip extension not available");
+?>
+--FILE--
+<?php
+$zip = new ZipArchive();
+$zip->open(__DIR__ . "/bug81420.zip");
+$destination = __DIR__ . "/bug81420";
+mkdir($destination);
+$zip->extractTo($destination);
+var_dump(file_exists("$destination/nt1/zzr_noharm.php"));
+?>
+--CLEAN--
+<?php
+$destination = __DIR__ . "/bug81420";
+@unlink("$destination/nt1/zzr_noharm.php");
+@rmdir("$destination/nt1");
+@rmdir($destination);
+?>
+--EXPECT--
+bool(true)
diff --git a/ext/zip/tests/bug81420.zip b/ext/zip/tests/bug81420.zip
new file mode 100644
index 0000000000000000000000000000000000000000..2e9686cb98ab15e5703d48bf52c4b9982b7bb05d
GIT binary patch
literal 218
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z?HTVgzGrpTt<vf`fBL+K&Z(=~Co}>!Yz=<!^wRaqm(Ob(UU8qw%n;zs$Rxsm%XAf>
w`5>SGCUM!t1(j!HkYET}w`}&I1=ks$?*BU(nGWz~Wdj+)2!t6xItFYa0HHoW;{X5v

literal 0
HcmV?d00001

-- 
2.33.0.windows.1