From de498a528cd6fc36c4bb22bf8dec6558e21cc9b6 Mon Sep 17 00:00:00 2001 From: David Kalnischkies Date: Sun, 4 Mar 2012 22:50:21 +0100 Subject: * apt-pkg/acquire-item.cc: - remove 'old' InRelease file if we can't get a new one before proceeding with Release.gpg to avoid the false impression of a still trusted repository by a (still present) old InRelease file. Thanks to Simon Ruderich for reporting this issue! (CVE-2012-0214) Effected are all versions >= 0.8.11 Possible attack summary: - Attacker needs to find a user which has run at least one successful 'apt-get update' against an archive providing InRelease files. - Create a Packages file with his preferred content. - Attacker then prevents the download of InRelease, Release and Release.gpg (alternatively he creates a valid Release file and sends this, the other two files need to be missing either way). - User updates against this, getting the modified Packages file without any indication of being unsigned (beside the "Ign InRelease" and "Ign Release.gpg" in the output of 'apt-get update'). => deb files from this source are considered 'trusted' (and therefore the user isn't asked for an additional confirmation before install) --- apt-pkg/acquire-item.cc | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'apt-pkg') diff --git a/apt-pkg/acquire-item.cc b/apt-pkg/acquire-item.cc index 4e6fb7ff9..545a57d37 100644 --- a/apt-pkg/acquire-item.cc +++ b/apt-pkg/acquire-item.cc @@ -1598,6 +1598,13 @@ void pkgAcqMetaClearSig::Failed(string Message,pkgAcquire::MethodConfig *Cnf) /* { if (AuthPass == false) { + // Remove the 'old' InRelease file if we try Release.gpg now as otherwise + // the file will stay around and gives a false-auth impression (CVE-2012-0214) + string FinalFile = _config->FindDir("Dir::State::lists"); + FinalFile.append(URItoFileName(RealURI)); + if (FileExists(FinalFile)) + unlink(FinalFile.c_str()); + new pkgAcqMetaSig(Owner, MetaSigURI, MetaSigURIDesc, MetaSigShortDesc, MetaIndexURI, MetaIndexURIDesc, MetaIndexShortDesc, -- cgit v1.2.3