kconfig: remove shell commands in .desktop files

CVE-2019-14744
This commit is contained in:
Helmut Pozimski 2019-08-08 16:19:14 +02:00
parent d3612486c6
commit c67d44f2fd
2 changed files with 148 additions and 1 deletions

View file

@ -0,0 +1,147 @@
From 5d3e71b1d2ecd2cb2f910036e614ffdfc895aa22 Mon Sep 17 00:00:00 2001
From: David Faure <faure@kde.org>
Date: Wed, 7 Aug 2019 09:35:36 +0200
Subject: Security: remove support for $(...) in config keys with [$e] marker.
Summary:
It is very unclear at this point what a valid use case for this feature
would possibly be. The old documentation only mentions $(hostname) as
an example, which can be done with $HOSTNAME instead.
Note that $(...) is still supported in Exec lines of desktop files,
this does not require [$e] anyway (and actually works better without it,
otherwise the $ signs need to be doubled to obey kconfig $e escaping rules...).
Test Plan:
ctest passes; various testcases with $(...) in desktop files,
directory files, and config files, no longer execute commands.
Reviewers: mdawson, aacid, broulik, davidedmundson, kossebau, apol, sitter, security-team
Reviewed By: mdawson, davidedmundson
Subscribers: ZaWertun, rikmills, fvogt, ngraham, kde-frameworks-devel
Tags: #frameworks
Differential Revision: https://phabricator.kde.org/D22979
---
autotests/kconfigtest.cpp | 10 ++--------
docs/options.md | 11 ++++-------
src/core/kconfig.cpp | 37 +------------------------------------
3 files changed, 7 insertions(+), 51 deletions(-)
diff --git a/autotests/kconfigtest.cpp b/autotests/kconfigtest.cpp
index 410b5b8..9af3b46 100644
--- autotests/kconfigtest.cpp
+++ autotests/kconfigtest.cpp
@@ -38,7 +38,7 @@
#include <utime.h>
#endif
#ifndef Q_OS_WIN
-#include <unistd.h> // gethostname
+#include <unistd.h> // getuid
#endif
KCONFIGGROUP_DECLARE_ENUM_QOBJECT(KConfigTest, Testing)
@@ -546,14 +546,8 @@ void KConfigTest::testPath()
QCOMPARE(group.readPathEntry("withBraces", QString()), QString("file://" + HOMEPATH));
QVERIFY(group.hasKey("URL"));
QCOMPARE(group.readEntry("URL", QString()), QString("file://" + HOMEPATH));
-#if !defined(Q_OS_WIN32) && !defined(Q_OS_MAC)
- // I don't know if this will work on windows
- // This test hangs on OS X
QVERIFY(group.hasKey("hostname"));
- char hostname[256];
- QVERIFY(::gethostname(hostname, sizeof(hostname)) == 0);
- QCOMPARE(group.readEntry("hostname", QString()), QString::fromLatin1(hostname));
-#endif
+ QCOMPARE(group.readEntry("hostname", QString()), QStringLiteral("(hostname)")); // the $ got removed because empty var name
QVERIFY(group.hasKey("noeol"));
QCOMPARE(group.readEntry("noeol", QString()), QString("foo"));
diff --git a/docs/options.md b/docs/options.md
index c634c00..4a6e9bc 100644
--- docs/options.md
+++ docs/options.md
@@ -67,18 +67,15 @@ environment variables (and `XDG_CONFIG_HOME` in particular).
Shell Expansion
---------------
-If an entry is marked with `$e`, environment variables and shell commands will
-be expanded.
+If an entry is marked with `$e`, environment variables will be expanded.
Name[$e]=$USER
- Host[$e]=$(hostname)
When the "Name" entry is read `$USER` will be replaced with the value of the
-`$USER` environment variable, and `$(hostname)` will be replaced with the output
-of the `hostname` command.
+`$USER` environment variable.
-Note that the application will replace `$USER` and `$(hostname)` with their
-respective expanded values after saving. To prevent this combine the `$e` option
+Note that the application will replace `$USER` with its
+expanded value after saving. To prevent this combine the `$e` option
with `$i` (immmutable) option. For example:
Name[$ei]=$USER
diff --git a/src/core/kconfig.cpp b/src/core/kconfig.cpp
index e1b11ed..f6824ce 100644
--- src/core/kconfig.cpp
+++ src/core/kconfig.cpp
@@ -28,19 +28,6 @@
#include <cstdlib>
#include <fcntl.h>
-#ifdef _MSC_VER
-static inline FILE *popen(const char *cmd, const char *mode)
-{
- return _popen(cmd, mode);
-}
-static inline int pclose(FILE *stream)
-{
- return _pclose(stream);
-}
-#else
-#include <unistd.h>
-#endif
-
#include "kconfigbackend_p.h"
#include "kconfiggroup.h"
@@ -183,29 +170,7 @@ QString KConfigPrivate::expandString(const QString &value)
int nDollarPos = aValue.indexOf(QLatin1Char('$'));
while (nDollarPos != -1 && nDollarPos + 1 < aValue.length()) {
// there is at least one $
- if (aValue[nDollarPos + 1] == QLatin1Char('(')) {
- int nEndPos = nDollarPos + 1;
- // the next character is not $
- while ((nEndPos <= aValue.length()) && (aValue[nEndPos] != QLatin1Char(')'))) {
- nEndPos++;
- }
- nEndPos++;
- QString cmd = aValue.mid(nDollarPos + 2, nEndPos - nDollarPos - 3);
-
- QString result;
-
-// FIXME: wince does not have pipes
-#ifndef _WIN32_WCE
- FILE *fs = popen(QFile::encodeName(cmd).data(), "r");
- if (fs) {
- QTextStream ts(fs, QIODevice::ReadOnly);
- result = ts.readAll().trimmed();
- pclose(fs);
- }
-#endif
- aValue.replace(nDollarPos, nEndPos - nDollarPos, result);
- nDollarPos += result.length();
- } else if (aValue[nDollarPos + 1] != QLatin1Char('$')) {
+ if (aValue[nDollarPos + 1] != QLatin1Char('$')) {
int nEndPos = nDollarPos + 1;
// the next character is not $
QStringRef aVarName;
--
cgit v1.1

View file

@ -1,7 +1,7 @@
# Template file for 'kconfig'
pkgname=kconfig
version=5.60.0
revision=1
revision=2
build_style=cmake
configure_args="-DBUILD_TESTING=OFF"
hostmakedepends="kcoreaddons extra-cmake-modules qt5-host-tools qt5-tools-devel"