Ubuntu je objavio nadogradnju programskog paketa PAM koja otklanja brojne propuste čije bi uspješno iskorištavanje moglo dovesti do izvođenja DoS napada, čitanja proizvoljnih datoteka, pristupa osjetljivim podacima i stjecanja povećanih ovlasti na ranjivom sustavu.
Paket:
pam 0.x, pam 1.x
Operacijski sustavi:
Ubuntu Linux 8.04, Ubuntu Linux 10.04, Ubuntu Linux 10.10, Ubuntu Linux 11.04
Kritičnost:
5.7
Problem:
neodgovarajuće rukovanje datotekama, pogreška u programskoj komponenti
Iskorištavanje:
lokalno
Posljedica:
dobivanje većih privilegija, otkrivanje osjetljivih informacija, uskraćivanje usluga (DoS)
Neki od propusta se odnose na nepravilnu implementaciju konfiguracijskih datoteka koje ne sadržavaju korisnička imena sa ASCII znakovima. Također se javljaju problemi u radu određenih modula kao što su pam_xauth, pam_env, pam_mail i pam_namespace.
Posljedica:
Uspješni napadač može iskoristiti propuste za izvođenje DoS napada, stjecanje povećanih ovlasti te pregled određenih podataka.
Rješenje:
Budući da je dostupna odgovarajuća nadogradnja, svi se korisnici upućuju na primjenu iste.
==========================================================================
Ubuntu Security Notice USN-1140-1
May 30, 2011
pam vulnerabilities
==========================================================================
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 11.04
- Ubuntu 10.10
- Ubuntu 10.04 LTS
- Ubuntu 8.04 LTS
Summary:
An attacker could cause PAM to read or delete arbitrary files or cause it
to crash.
Software Description:
- pam: Pluggable Authentication Modules
Details:
Marcus Granado discovered that PAM incorrectly handled configuration files
with non-ASCII usernames. A remote attacker could use this flaw to cause a
denial of service, or possibly obtain login access with a different users
username. This issue only affected Ubuntu 8.04 LTS. (CVE-2009-0887)
It was discovered that the PAM pam_xauth, pam_env and pam_mail modules
incorrectly handled dropping privileges when performing operations. A local
attacker could use this flaw to read certain arbitrary files, and access
other sensitive information. (CVE-2010-3316, CVE-2010-3430, CVE-2010-3431,
CVE-2010-3435)
It was discovered that the PAM pam_namespace module incorrectly cleaned the
environment during execution of the namespace.init script. A local attacker
could use this flaw to possibly gain privileges. (CVE-2010-3853)
It was discovered that the PAM pam_xauth module incorrectly handled certain
failures. A local attacker could use this flaw to delete certain unintended
files. (CVE-2010-4706)
It was discovered that the PAM pam_xauth module incorrectly verified
certain file properties. A local attacker could use this flaw to cause a
denial of service. (CVE-2010-4707)
Update instructions:
The problem can be corrected by updating your system to the following
package versions:
Ubuntu 11.04:
libpam-modules 1.1.2-2ubuntu8.2
Ubuntu 10.10:
libpam-modules 1.1.1-4ubuntu2.2
Ubuntu 10.04 LTS:
libpam-modules 1.1.1-2ubuntu5.2
Ubuntu 8.04 LTS:
libpam-modules 0.99.7.1-5ubuntu6.3
In general, a standard system update will make all the necessary changes.
References:
CVE-2009-0887, CVE-2010-3316, CVE-2010-3430, CVE-2010-3431,
CVE-2010-3435, CVE-2010-3853, CVE-2010-4706, CVE-2010-4707
Package Information:
https://launchpad.net/ubuntu/+source/pam/1.1.2-2ubuntu8.2
https://launchpad.net/ubuntu/+source/pam/1.1.1-4ubuntu2.2
https://launchpad.net/ubuntu/+source/pam/1.1.1-2ubuntu5.2
https://launchpad.net/ubuntu/+source/pam/0.99.7.1-5ubuntu6.3
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