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Gentoo Linux Security Advisory GLSA 200712-14 |
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http://security.gentoo.org/ |
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Severity: High |
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Title: CUPS: Multiple vulnerabilities |
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Date: December 18, 2007 |
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Bugs: #199195, #201042, #201570 |
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ID: 200712-14 |
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Synopsis |
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======== |
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|
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Multiple vulnerabilities have been discovered in CUPS, allowing for the |
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remote execution of arbitrary code and a Denial of Service. |
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Background |
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========== |
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|
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CUPS provides a portable printing layer for UNIX-based operating |
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systems. The alternate pdftops filter is a CUPS filter used to convert |
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PDF files to the Postscript format via Poppler; the filter is installed |
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by default in Gentoo Linux. |
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|
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Affected packages |
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================= |
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|
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------------------------------------------------------------------- |
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Package / Vulnerable / Unaffected |
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------------------------------------------------------------------- |
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1 net-print/cups < 1.3.5 *>= 1.2.12-r4 |
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>= 1.3.5 |
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|
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Description |
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=========== |
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|
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Wei Wang (McAfee AVERT Research) discovered an integer underflow in the |
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asn1_get_string() function of the SNMP backend, leading to a |
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stack-based buffer overflow when handling SNMP responses |
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(CVE-2007-5849). Elias Pipping (Gentoo) discovered that the alternate |
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pdftops filter creates temporary files with predictable file names when |
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reading from standard input (CVE-2007-6358). Furthermore, the |
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resolution of a Denial of Service vulnerability covered in GLSA |
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200703-28 introduced another Denial of Service vulnerability within SSL |
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handling (CVE-2007-4045). |
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|
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Impact |
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====== |
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|
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A remote attacker on the local network could exploit the first |
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vulnerability to execute arbitrary code with elevated privileges by |
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sending specially crafted SNMP messages as a response to an SNMP |
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broadcast request. A local attacker could exploit the second |
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vulnerability to overwrite arbitrary files with the privileges of the |
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user running the CUPS spooler (usually lp) by using symlink attacks. A |
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remote attacker could cause a Denial of Service condition via the third |
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vulnerability when SSL is enabled in CUPS. |
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|
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Workaround |
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========== |
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To disable SNMP support in CUPS, you have have to manually delete the |
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file "/usr/libexec/cups/backend/snmp". Please note that the file is |
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reinstalled if you merge CUPS again later. To disable the pdftops |
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filter, delete all lines referencing "pdftops" in CUPS' "mime.convs" |
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configuration file. To work around the third vulnerability, disable SSL |
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support via the corresponding USE flag. |
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Resolution |
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========== |
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All CUPS users should upgrade to the latest version: |
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# emerge --sync |
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# emerge --ask --oneshot --verbose ">=net-print/cups-1.2.12-r4" |
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References |
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========== |
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[ 1 ] CVE-2007-4045 |
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http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2007-4045 |
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[ 2 ] CVE-2007-5849 |
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http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2007-5849 |
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[ 3 ] CVE-2007-6358 |
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http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2007-6358 |
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[ 4 ] GLSA 200703-28 |
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http://www.gentoo.org/security/en/glsa/glsa-200703-28.xml |
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Availability |
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============ |
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This GLSA and any updates to it are available for viewing at |
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the Gentoo Security Website: |
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http://security.gentoo.org/glsa/glsa-200712-14.xml |
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Concerns? |
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========= |
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Security is a primary focus of Gentoo Linux and ensuring the |
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confidentiality and security of our users machines is of utmost |
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importance to us. Any security concerns should be addressed to |
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security@g.o or alternatively, you may file a bug at |
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http://bugs.gentoo.org. |
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License |
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======= |
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Copyright 2007 Gentoo Foundation, Inc; referenced text |
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belongs to its owner(s). |
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The contents of this document are licensed under the |
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Creative Commons - Attribution / Share Alike license. |
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|
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http://creativecommons.org/licenses/by-sa/2.5 |
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