CVSS2
Attack Vector
LOCAL
Attack Complexity
HIGH
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:L/AC:H/Au:N/C:C/I:C/A:C
EPSS
Percentile
5.1%
Due to the way the pam_ssh_agent_auth PAM module was built in Scientific Linux 6, the glibc’s error() function was called rather than the intended error() function in pam_ssh_agent_auth to report errors. As these two functions expect different arguments, it was possible for an attacker to cause an application using pam_ssh_agent_auth to crash, disclose portions of its memory or, potentially, execute arbitrary code. (CVE-2012-5536)
Note that the pam_ssh_agent_auth module is not used in Scientific Linux 6 by default.
This update also fixes the following bugs :
All possible options for the new RequiredAuthentications directive were not documented in the sshd_config man page. This update improves the man page to document all the possible options.
When stopping one instance of the SSH daemon (sshd), the sshd init script (/etc/rc.d/init.d/sshd) stopped all sshd processes regardless of the PID of the processes.
This update improves the init script so that it only kills processes with the relevant PID. As a result, the init script now works more reliably in a multi-instance environment.
Due to a regression, the ssh-copy-id command returned an exit status code of zero even if there was an error in copying the key to a remote host. With this update, a patch has been applied and ssh-copy-id now returns a non-zero exit code if there is an error in copying the SSH certificate to a remote host.
When SELinux was disabled on the system, no on-disk policy was installed, a user account was used for a connection, and no ‘~/.ssh’ configuration was present in that user’s home directory, the SSH client terminated unexpectedly with a segmentation fault when attempting to connect to another system. A patch has been provided to address this issue and the crashes no longer occur in the described scenario.
The ‘HOWTO’ document /usr/share/doc/openssh-ldap-5.3p1/HOWTO.ldap-keys incorrectly documented the use of the AuthorizedKeysCommand directive. This update corrects the document.
This update also adds the following enhancements :
When attempting to enable SSH for use with a Common Access Card (CAC), the ssh-agent utility read all the certificates in the card even though only the ID certificate was needed. Consequently, if a user entered their PIN incorrectly, then the CAC was locked, as a match for the PIN was attempted against all three certificates. With this update, ssh-add does not try the same PIN for every certificate if the PIN fails for the first one. As a result, the CAC will not be disabled if a user enters their PIN incorrectly.
This update adds a ‘netcat mode’ to SSH. The ‘ssh -W host:port …’ command connects standard input and output (stdio) on a client to a single port on a server.
As a result, SSH can be used to route connections via intermediate servers.
Due to a bug, arguments for the RequiredAuthentications2 directive were not stored in a Match block.
Consequently, parsing of the config file was not in accordance with the man sshd_config documentation. This update fixes the bug and users can now use the required authentication feature to specify a list of authentication methods as expected according to the man page.
After installing this update, the OpenSSH server daemon (sshd) will be restarted automatically.
#%NASL_MIN_LEVEL 70300
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text is (C) Scientific Linux.
#
include('deprecated_nasl_level.inc');
include('compat.inc');
if (description)
{
script_id(64954);
script_version("1.6");
script_set_attribute(attribute:"plugin_modification_date", value:"2021/01/14");
script_cve_id("CVE-2012-5536");
script_name(english:"Scientific Linux Security Update : openssh on SL6.x i386/x86_64 (20130221)");
script_summary(english:"Checks rpm output for the updated packages");
script_set_attribute(
attribute:"synopsis",
value:
"The remote Scientific Linux host is missing one or more security
updates."
);
script_set_attribute(
attribute:"description",
value:
"Due to the way the pam_ssh_agent_auth PAM module was built in
Scientific Linux 6, the glibc's error() function was called rather
than the intended error() function in pam_ssh_agent_auth to report
errors. As these two functions expect different arguments, it was
possible for an attacker to cause an application using
pam_ssh_agent_auth to crash, disclose portions of its memory or,
potentially, execute arbitrary code. (CVE-2012-5536)
Note that the pam_ssh_agent_auth module is not used in Scientific
Linux 6 by default.
This update also fixes the following bugs :
- All possible options for the new RequiredAuthentications
directive were not documented in the sshd_config man
page. This update improves the man page to document all
the possible options.
- When stopping one instance of the SSH daemon (sshd), the
sshd init script (/etc/rc.d/init.d/sshd) stopped all
sshd processes regardless of the PID of the processes.
This update improves the init script so that it only
kills processes with the relevant PID. As a result, the
init script now works more reliably in a multi-instance
environment.
- Due to a regression, the ssh-copy-id command returned an
exit status code of zero even if there was an error in
copying the key to a remote host. With this update, a
patch has been applied and ssh-copy-id now returns a
non-zero exit code if there is an error in copying the
SSH certificate to a remote host.
- When SELinux was disabled on the system, no on-disk
policy was installed, a user account was used for a
connection, and no '~/.ssh' configuration was present in
that user's home directory, the SSH client terminated
unexpectedly with a segmentation fault when attempting
to connect to another system. A patch has been provided
to address this issue and the crashes no longer occur in
the described scenario.
- The 'HOWTO' document
/usr/share/doc/openssh-ldap-5.3p1/HOWTO.ldap-keys
incorrectly documented the use of the
AuthorizedKeysCommand directive. This update corrects
the document.
This update also adds the following enhancements :
- When attempting to enable SSH for use with a Common
Access Card (CAC), the ssh-agent utility read all the
certificates in the card even though only the ID
certificate was needed. Consequently, if a user entered
their PIN incorrectly, then the CAC was locked, as a
match for the PIN was attempted against all three
certificates. With this update, ssh-add does not try the
same PIN for every certificate if the PIN fails for the
first one. As a result, the CAC will not be disabled if
a user enters their PIN incorrectly.
- This update adds a 'netcat mode' to SSH. The 'ssh -W
host:port ...' command connects standard input and
output (stdio) on a client to a single port on a server.
As a result, SSH can be used to route connections via
intermediate servers.
- Due to a bug, arguments for the RequiredAuthentications2
directive were not stored in a Match block.
Consequently, parsing of the config file was not in
accordance with the man sshd_config documentation. This
update fixes the bug and users can now use the required
authentication feature to specify a list of
authentication methods as expected according to the man
page.
After installing this update, the OpenSSH server daemon (sshd) will be
restarted automatically."
);
# https://listserv.fnal.gov/scripts/wa.exe?A2=ind1302&L=scientific-linux-errata&T=0&P=4416
script_set_attribute(
attribute:"see_also",
value:"http://www.nessus.org/u?58d13ca5"
);
script_set_attribute(attribute:"solution", value:"Update the affected packages.");
script_set_cvss_base_vector("CVSS2#AV:L/AC:H/Au:N/C:C/I:C/A:C");
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:fermilab:scientific_linux:openssh");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:fermilab:scientific_linux:openssh-askpass");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:fermilab:scientific_linux:openssh-clients");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:fermilab:scientific_linux:openssh-debuginfo");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:fermilab:scientific_linux:openssh-ldap");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:fermilab:scientific_linux:openssh-server");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:fermilab:scientific_linux:pam_ssh_agent_auth");
script_set_attribute(attribute:"cpe", value:"x-cpe:/o:fermilab:scientific_linux");
script_set_attribute(attribute:"vuln_publication_date", value:"2013/02/22");
script_set_attribute(attribute:"patch_publication_date", value:"2013/02/21");
script_set_attribute(attribute:"plugin_publication_date", value:"2013/03/01");
script_set_attribute(attribute:"generated_plugin", value:"current");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_copyright(english:"This script is Copyright (C) 2013-2021 and is owned by Tenable, Inc. or an Affiliate thereof.");
script_family(english:"Scientific Linux Local Security Checks");
script_dependencies("ssh_get_info.nasl");
script_require_keys("Host/local_checks_enabled", "Host/cpu", "Host/RedHat/release", "Host/RedHat/rpm-list");
exit(0);
}
include("audit.inc");
include("global_settings.inc");
include("misc_func.inc");
include("rpm.inc");
if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
release = get_kb_item("Host/RedHat/release");
if (isnull(release) || "Scientific Linux " >!< release) audit(AUDIT_HOST_NOT, "running Scientific Linux");
os_ver = pregmatch(pattern: "Scientific Linux.*release ([0-9]+(\.[0-9]+)?)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Scientific Linux");
os_ver = os_ver[1];
if (! preg(pattern:"^6([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "Scientific Linux 6.x", "Scientific Linux " + os_ver);
if (!get_kb_item("Host/RedHat/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);
cpu = get_kb_item("Host/cpu");
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if (cpu >!< "x86_64" && cpu !~ "^i[3-6]86$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "Scientific Linux", cpu);
flag = 0;
if (rpm_check(release:"SL6", reference:"openssh-5.3p1-84.1.el6")) flag++;
if (rpm_check(release:"SL6", reference:"openssh-askpass-5.3p1-84.1.el6")) flag++;
if (rpm_check(release:"SL6", reference:"openssh-clients-5.3p1-84.1.el6")) flag++;
if (rpm_check(release:"SL6", reference:"openssh-debuginfo-5.3p1-84.1.el6")) flag++;
if (rpm_check(release:"SL6", reference:"openssh-ldap-5.3p1-84.1.el6")) flag++;
if (rpm_check(release:"SL6", reference:"openssh-server-5.3p1-84.1.el6")) flag++;
if (rpm_check(release:"SL6", reference:"pam_ssh_agent_auth-0.9.3-84.1.el6")) flag++;
if (flag)
{
security_report_v4(
port : 0,
severity : SECURITY_WARNING,
extra : rpm_report_get()
);
exit(0);
}
else
{
tested = pkg_tests_get();
if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
else audit(AUDIT_PACKAGE_NOT_INSTALLED, "openssh / openssh-askpass / openssh-clients / openssh-debuginfo / etc");
}