[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

RC bug status for perl packages (re '.' in @INC removal)


As you will see from the below DSA, a class of vulnerabilities in
perl programs has been announced today. We have fixed the worst parts of
this in Debian, but ultimately we'd like to (in keeping with upstream's
intentions for 5.26) remove the current directory from the module search
path altogether.

At the moment, this would cause around 40 packages to FTBFS (that was
the number of jessie - it will be a bit different for sid).

In the near term, changing the default is a matter of uncommenting a line
in a conffile (and can therefore be easily reverted by the user if needed).

I'd like to upload such a change to sid ASAP (probably just after the
initial sid upload, due any minute now, migrates to testing). If the
impact of that measured against sid/stretch is manageable, we'd also like
to consider making the change by default in a future point release,
although the number of packages that need updates may still be too large;
we'd obviously discuss that with you in the normal way via a transition

Are you happy for us to introduce such a change in sid later this week,
and start filing RC bugs about problems in other packages caused by
the change?


----- Forwarded message from Salvatore Bonaccorso <carnil@debian.org> -----

Date: Mon, 25 Jul 2016 14:18:38 +0000
From: Salvatore Bonaccorso <carnil@debian.org>
To: debian-security-announce@lists.debian.org
Subject: [SECURITY] [DSA 3628-1] perl security update

Debian Security Advisory DSA-3628-1                   security@debian.org
https://www.debian.org/security/                     Salvatore Bonaccorso
July 25, 2016                         https://www.debian.org/security/faq

Package        : perl
CVE ID         : CVE-2016-1238 CVE-2016-6185
Debian Bug     : 829578

Multiple vulnerabilities were discovered in the implementation of the
Perl programming language. The Common Vulnerabilities and Exposures
project identifies the following problems:


    John Lightsey and Todd Rinaldo reported that the opportunistic
    loading of optional modules can make many programs unintentionally
    load code from the current working directory (which might be changed
    to another directory without the user realising) and potentially
    leading to privilege escalation, as demonstrated in Debian with
    certain combinations of installed packages.

    The problem relates to Perl loading modules from the includes
    directory array ("@INC") in which the last element is the current
    directory ("."). That means that, when "perl" wants to load a module
    (during first compilation or during lazy loading of a module in run-
    time), perl will look for the module in the current directory at the
    end, since '.' is the last include directory in its array of include
    directories to seek. The issue is with requiring libraries that are
    in "." but are not otherwise installed.

    With this update several modules which are known to be vulnerable
    are updated to not load modules from current directory.

    Additionally the update allows configurable removal of "." from @INC
    in /etc/perl/sitecustomize.pl for a transitional period. It is
    recommended to enable this setting if the possible breakage for a
    specific site has been evaluated. Problems in packages provided in
    Debian resulting from the switch to the removal of '.' from @INC
    should be reported to the Perl maintainers at
    perl@packages.debian.org .

    It is planned to switch to the default removal of '.' in @INC in a
    subsequent update to perl via a point release if possible, and in
    any case for the upcoming stable release Debian 9 (stretch).


    It was discovered that XSLoader, a core module from Perl to
    dynamically load C libraries into Perl code, could load shared
    library from incorrect location. XSLoader uses caller() information
    to locate the .so file to load. This can be incorrect if
    XSLoader::load() is called in a string eval. An attacker can take
    advantage of this flaw to execute arbitrary code.

For the stable distribution (jessie), these problems have been fixed in
version 5.20.2-3+deb8u6. Additionally this update includes the
following updated packages to address optional module loading
vulnerabilities related to CVE-2016-1238, or to address build failures
which occur when '.' is removed from @INC:

 - cdbs 0.4.130+deb8u1
 - debhelper 9.20150101+deb8u2
 - devscripts 2.15.3+deb8u1
 - exim4 4.84.2-2+deb8u1
 - libintl-perl 1.23-1+deb8u1
 - libmime-charset-perl 1.011.1-1+deb8u2
 - libmime-encwords-perl 1.014.3-1+deb8u1
 - libmodule-build-perl 0.421000-2+deb8u1
 - libnet-dns-perl 0.81-2+deb8u1
 - libsys-syslog-perl 0.33-1+deb8u1
 - libunicode-linebreak-perl 0.0.20140601-2+deb8u2

We recommend that you upgrade your perl packages.

Further information about Debian Security Advisories, how to apply
these updates to your system and frequently asked questions can be
found at: https://www.debian.org/security/

Mailing list: debian-security-announce@lists.debian.org

----- End forwarded message -----

Reply to: