ark: fix CVE-2020-16116

This commit is contained in:
John 2020-07-31 15:57:51 +02:00
parent 2a69d81fb6
commit e2784594b8
3 changed files with 48 additions and 1 deletions

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@ -0,0 +1,46 @@
From 0df592524fed305d6fbe74ddf8a196bc9ffdb92f Mon Sep 17 00:00:00 2001
From: Elvis Angelaccio <elvis.angelaccio@kde.org>
Date: Wed, 29 Jul 2020 23:45:30 +0200
Subject: [PATCH] Fix vulnerability to path traversal attacks
Ark was vulnerable to directory traversal attacks because of
missing validation of file paths in the archive.
More details about this attack are available at:
https://github.com/snyk/zip-slip-vulnerability
Job::onEntry() is the only place where we can safely check the path of
every entry in the archive. There shouldn't be a valid reason
to have a "../" in an archive path, so we can just play safe and abort
the LoadJob if we detect such an entry. This makes impossibile to
extract this kind of malicious archives and perform the attack.
Thanks to Albert Astals Cid for suggesting to use QDir::cleanPath()
so that we can still allow loading of legitimate archives that
contain "../" in their paths but still resolve inside the extraction folder.
---
kerfuffle/jobs.cpp | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/kerfuffle/jobs.cpp b/kerfuffle/jobs.cpp
index fdaa48695..f73b56f86 100644
--- a/kerfuffle/jobs.cpp
+++ b/kerfuffle/jobs.cpp
@@ -180,6 +180,14 @@ void Job::onError(const QString & message, const QString & details)
void Job::onEntry(Archive::Entry *entry)
{
+ const QString entryFullPath = entry->fullPath();
+ if (QDir::cleanPath(entryFullPath).contains(QLatin1String("../"))) {
+ qCWarning(ARK) << "Possibly malicious archive. Detected entry that could lead to a directory traversal attack:" << entryFullPath;
+ onError(i18n("Could not load the archive because it contains ill-formed entries and might be a malicious archive."), QString());
+ onFinished(false);
+ return;
+ }
+
emit newEntry(entry);
}
--
GitLab

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@ -1,7 +1,7 @@
# Template file for 'ark'
pkgname=ark
version=20.04.3
revision=1
revision=2
build_style=cmake
hostmakedepends="extra-cmake-modules qt5-devel qt5-qmake
kdoctools kconfig gettext pkg-config"