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Vulnerabilidades Cisco PIX e ASA |
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Quinta, 03 Maio 2007 17:07 |
| Sistemas Operativos Implicados: | Cisco IOS
| | Aplicações Implicadas: | Indefinido
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Foram reportadas várias vulnerabilidades para Cisco PIX e ASA, estas podem ser exploradas por actos maliciosos para ultrapassar determinadas medidas de segurança ou para causar DoS (Denial of Service). A Cisco anunciou um boletim de segurança com informação detalhada sobre as mesmas. São destacadas duas vulnerabilidades que afectam a autenticação LDAP(Lightweight Directory Access Protocol), e outras duas relacionadas com VPNs (Virtual Private Networks ). I.
Descrição
Some vulnerabilities have been reported in Cisco PIX and ASA, which can
be exploited by malicious people to bypass certain security
restrictions or cause a DoS (Denial of Service).
1) An unspecified error exists when using the LDAP authentication
mechanism, which can be exploited to bypass the authentication and gain
access to the device or the network.
Successful exploitation requires that the device uses the Layer 2
Tunneling Protocol (L2TP) and is configured to use LDAP servers with
another protocol other than PAP for authentication, or that the device
offers remote management access (telnet, SSH, HTTP) and uses an LDAP
AAA server for authentication.
2) An unspecified error when using VPN connections configured with
password expiry can be exploited to cause a DoS.
Successful exploitation requires that the tunnel group is configured
with password expiry. In order to exploit this in IPSec VPN
connections, an attacker also needs to know the group name and group
password.
3) A race condition within the processing of non-standard SSL sessions
in the SSL VPN server of Cisco ASA appliances can be exploited to cause
the device to reload.
Successful exploitation requires that clientless SSL is used.
4) An error within the DHCP relay agent when handling DHCPACK messages
can be exploited to cause a DoS due to memory exhaustion by sending a
large number of DHCP requests to a vulnerable device.
Successful exploitation requires that devices are configured to use the
DHCP relay agent.
Solution:
Apply updated software versions. Please see vendor advisories for
details.
Provided and/or discovered by:
1-3) Reported by the vendor.
4) Lisa Sittler and Grant Deffenbaugh, CERT/CC.
Original Advisory:
Cisco:
http://www.cisco.com/warp/public/707/cisco-sa-20070502-asa.shtml
http://www.cisco.com/warp/public/707/cisco-sr-20070502-pix.shtml
http://www.cisco.com/en/US/products/p...ecurity_response09186a0080833172.html
http://www.cisco.com/en/US/products/p...ligence_response09186a008083316f.html
US-CERT VU#530057:
http://www.kb.cert.org/vuls/id/530057
Other References:
US-CERT VU#210876:
http://www.kb.cert.org/vuls/id/210876
US-CERT VU#337508:
http://www.kb.cert.org/vuls/id/337508
II. Referências
Secunia:
http://secunia.com/advisories/25109/
US-CERT:
http://www.us-cert.gov/current/index.html#cisco_releases_security_advisory_to1
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