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Gentoo Linux Security Advisory GLSA 200405-19 |
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http://security.gentoo.org/ |
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|
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Severity: Normal |
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Title: Opera telnet URI handler file creation/truncation |
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vulnerability |
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Date: May 25, 2004 |
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Bugs: #50857 |
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ID: 200405-19 |
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|
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|
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Synopsis |
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======== |
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|
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A vulnerability exists in Opera's telnet URI handler that may allow a |
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remote attacker to overwrite arbitrary files. |
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|
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Background |
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========== |
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|
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Opera is a multi-platform web browser. |
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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-www/opera < 7.50_beta1 >= 7.50_beta1 |
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|
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Description |
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=========== |
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|
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The telnet URI handler in Opera does not check for leading '-' |
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characters in the host name. Consequently, a maliciously-crafted |
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telnet:// link may be able to pass options to the telnet program |
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itself. One example would be the following: |
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|
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telnet://-nMyFile |
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|
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If MyFile exists in the user's home directory and the user clicking on |
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the link has write permissions to it, the contents of the file will be |
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overwritten with the output of the telnet trace information. If MyFile |
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does not exist, the file will be created in the user's home directory. |
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|
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Impact |
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====== |
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|
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This exploit has two possible impacts. First, it may create new files |
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in the user's home directory. Second, and far more serious, it may |
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overwrite existing files that the user has write permissions to. An |
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attacker with some knowledge of a user's home directory might be able |
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to destroy important files stored within. |
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|
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Workaround |
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========== |
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|
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Disable the telnet URI handler from within Opera. |
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|
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Resolution |
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========== |
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|
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All Opera users are encouraged to upgrade to the latest version of the |
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program: |
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|
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# emerge sync |
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|
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# emerge -pv ">=net-www/opera-7.50_beta1" |
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# emerge ">=net-www/opera-7.50_beta1" |
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|
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References |
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========== |
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|
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[ 1 ] iDEFENSE Security Advisory 05.12.04 |
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http://www.idefense.com/application/poi/display?id=104&type=vulnerabilities&flashstatus=true |
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|
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Availability |
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============ |
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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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|
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http://security.gentoo.org/glsa/glsa-200405-19.xml |
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|
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Concerns? |
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========= |
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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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|
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License |
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======= |
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|
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Copyright 2004 Gentoo Technologies, Inc; referenced text |
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belongs to its owner(s). |
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|
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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/1.0 |