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TITLE:
eCryptfs Multiple Security Issues

SECUNIA ADVISORY ID:
SA45563

VERIFY ADVISORY:
Secunia.com
http://secunia.com/advisories/45563/
Customer Area (Credentials Required)
https://ca.secunia.com/?page=viewadvisory&vuln_id=45563

RELEASE DATE:
2011-08-11

DISCUSS ADVISORY:
http://secunia.com/advisories/45563/#comments

AVAILABLE ON SITE AND IN CUSTOMER AREA:
 * Last Update
 * Popularity
 * Comments
 * Criticality Level
 * Impact
 * Where
 * Solution Status
 * Operating System / Software
 * CVE Reference(s)

http://secunia.com/advisories/45563/

ONLY AVAILABLE IN CUSTOMER AREA:
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https://ca.secunia.com/?page=viewadvisory&vuln_id=45563

ONLY AVAILABLE WITH SECUNIA CSI AND SECUNIA PSI:
 * AUTOMATED SCANNING

http://secunia.com/vulnerability_scanning/personal/
http://secunia.com/vulnerability_scanning/corporate/wsus_sccm_3rd_third_party_patching/

DESCRIPTION:
Multiple security issues have been reported in eCryptfs, which can be
exploited by malicious, local users to disclose potentially sensitive
information, bypass certain security restrictions, manipulate certain
data, cause a DoS (Denial of Service), and potentially gain escalated
privileges.

1) Insufficient permission checks when mounting a mountpoint can be
exploited to mount arbitrary locations.

2) Insufficient permission checks when unmounting a mountpoint can be
exploited to unmount arbitrary locations.

3) Insufficient validation of the mount source directory can be
exploited to mount an arbitrary directory.

4) Incorrect error handling when modifying the mtab file can be
exploited to corrupt the mtab file and potentially unmount arbitrary
locations.

5) Keys are not properly handled when setting up new encrypted
directories, which can be exploited to manipulate keys when creating
a new user.

6) Incorrect permission handling during the recovery process can be
exploited to e.g. access another user's data.

7) An error exists when handling lock counters, which can be
exploited to overwrite arbitrary files.

SOLUTION:
Restrict access to trusted users only.

PROVIDED AND/OR DISCOVERED BY:
1, 2, 3) Vasiliy Kulikov and Dan Rosenberg
4) Dan Rosenberg and Marc Deslauriers
5, 6) Marc Deslauriers
7) Vasiliy Kulikov

ORIGINAL ADVISORY:
Launchpad Bug #732628:
https://bugs.launchpad.net/ecryptfs/+bug/732628

OTHER REFERENCES:
Further details available in Customer Area:
http://secunia.com/vulnerability_intelligence/

DEEP LINKS:
Further details available in Customer Area:
http://secunia.com/vulnerability_intelligence/

EXTENDED DESCRIPTION:
Further details available in Customer Area:
http://secunia.com/vulnerability_intelligence/

EXTENDED SOLUTION:
Further details available in Customer Area:
http://secunia.com/vulnerability_intelligence/

EXPLOIT:
Further details available in Customer Area:
http://secunia.com/vulnerability_intelligence/

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About:
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private users keeping their systems up to date against the latest
vulnerabilities.

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