electron/shell/app/command_line_args.cc
trop[bot] 40316df338
fix: -Wunsafe-buffer-usage warnings in IsUrlArg() (#43539)
* fix: -Wunsafe-buffer-usage warnings in IsUrlArg()

Co-authored-by: Charles Kerr <charles@charleskerr.com>

* chore: improve code comments for CheckCommandLineArguments()

Co-authored-by: Charles Kerr <charles@charleskerr.com>

* chore: reduce diffs from main

Co-authored-by: Charles Kerr <charles@charleskerr.com>

* refactor: CheckCommandLineArguments takes a StringVector arg

Fixes another buffer warning!

Co-authored-by: Charles Kerr <charles@charleskerr.com>

---------

Co-authored-by: trop[bot] <37223003+trop[bot]@users.noreply.github.com>
Co-authored-by: Charles Kerr <charles@charleskerr.com>
2024-09-04 22:51:54 -05:00

62 lines
1.9 KiB
C++

// Copyright (c) 2018 GitHub, Inc.
// Use of this source code is governed by the MIT license that can be
// found in the LICENSE file.
#include "shell/app/command_line_args.h"
#include <algorithm>
#include <locale>
#include "sandbox/policy/switches.h"
#include "shell/common/options_switches.h"
namespace {
#if BUILDFLAG(IS_WIN)
constexpr auto DashDash = base::CommandLine::StringViewType{L"--"};
#else
constexpr auto DashDash = base::CommandLine::StringViewType{"--"};
#endif
// we say it's a URL arg if it starts with a URI scheme that:
// 1. starts with an alpha, and
// 2. contains no spaces, and
// 3. is longer than one char (to ensure it's not a Windows drive path)
bool IsUrlArg(const base::CommandLine::StringViewType arg) {
const auto scheme_end = arg.find(':');
if (scheme_end == base::CommandLine::StringViewType::npos)
return false;
const auto& c_locale = std::locale::classic();
const auto isspace = [&](auto ch) { return std::isspace(ch, c_locale); };
const auto scheme = arg.substr(0U, scheme_end);
return std::size(scheme) > 1U && std::isalpha(scheme.front(), c_locale) &&
std::ranges::none_of(scheme, isspace);
}
} // namespace
namespace electron {
// Check for CVE-2018-1000006 issues. Return true iff argv looks safe.
// Sample exploit: 'exodus://aaaaaaaaa" --gpu-launcher="cmd" --aaaaa='
// Prevent it by returning false if any arg except '--' follows a URL arg.
// More info at https://www.electronjs.org/blog/protocol-handler-fix
bool CheckCommandLineArguments(const base::CommandLine::StringVector& argv) {
bool block_args = false;
for (const auto& arg : argv) {
if (arg == DashDash)
break;
if (block_args)
return false;
if (IsUrlArg(arg))
block_args = true;
}
return true;
}
bool IsSandboxEnabled(base::CommandLine* command_line) {
return command_line->HasSwitch(switches::kEnableSandbox) ||
!command_line->HasSwitch(sandbox::policy::switches::kNoSandbox);
}
} // namespace electron