Date: Thu, 30 Jul 2020 04:32:24 +0000 (UTC) From: "Tobias C. Berner" <tcberner@FreeBSD.org> To: ports-committers@freebsd.org, svn-ports-all@freebsd.org, svn-ports-head@freebsd.org Subject: svn commit: r543704 - head/archivers/ark/files Message-ID: <202007300432.06U4WOiT079662@repo.freebsd.org>
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Author: tcberner Date: Thu Jul 30 04:32:24 2020 New Revision: 543704 URL: https://svnweb.freebsd.org/changeset/ports/543704 Log: archivers/ark: security fix KDE Project Security Advisory ============================= Title: Ark: maliciously crafted archive can install files outside the extraction directory. Risk Rating: Important CVE: CVE-2020-16116 Versions: ark <= 20.04.3 Author: Elvis Angelaccio <elvis.angelaccio@kde.org> Date: 30 July 2020 Overview ======== A maliciously crafted archive with "../" in the file paths would install files anywhere in the user's home directory upon extraction. Proof of concept ================ For testing, an example of malicious archive can be found at https://github.com/jwilk/traversal-archives/releases/download/0/relative2.zip Impact ====== Users can unwillingly install files like a modified .bashrc, or a malicious script placed in ~/.config/autostart Workaround ========== Users should not use the 'Extract' context menu from the Dolphin file manager. Before extracting a downloaded archive using the Ark GUI, users should inspect it to make sure it doesn't contain entries with "../" in the file path. Solution ======== Ark 20.08.0 prevents loading of malicious archives and shows a warning message to the users. Alternatively, https://invent.kde.org/utilities/ark/-/commit/0df592524fed305d6fbe74ddf8a196bc9ffdb92f can be applied to previous releases. Credits ======= Thanks to Dominik Penner for finding and reporting this issue and thanks to Elvis Angelaccio and Albert Astals Cid for fixing it. Added: head/archivers/ark/files/ head/archivers/ark/files/patch-git_0d5952 (contents, props changed) Added: head/archivers/ark/files/patch-git_0d5952 ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/archivers/ark/files/patch-git_0d5952 Thu Jul 30 04:32:24 2020 (r543704) @@ -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 +--- kerfuffle/jobs.cpp ++++ 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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