A vulnerability in the remote access VPN feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to conduct a brute force attack in an attempt to identify valid username and password combinations or an authenticated, remote attacker to establish a clientless SSL VPN session with an unauthorized user. This vulnerability is due to improper separation of authentication, authorization, and accounting (AAA) between the remote access VPN feature and the HTTPS management and site-to-site VPN features. An attacker could exploit this vulnerability by specifying a default connection profile/tunnel group while conducting a brute force attack or while establishing a clientless SSL VPN session using valid credentials. A successful exploit could allow the attacker to achieve one or both of the following: Identify valid credentials that could then be used to establish an unauthorized remote access VPN session. Establish a clientless SSL VPN session (only when running Cisco ASA Software Release 9.16 or earlier). Notes: Establishing a client-based remote access VPN tunnel is not possible as these default connection profiles/tunnel groups do not and cannot have an IP address pool configured. This vulnerability does not allow an attacker to bypass authentication. To successfully establish a remote access VPN session, valid credentials are required, including a valid second factor if multi-factor authentication (MFA) is configured. Cisco will release software updates that address this vulnerability. There are workarounds that address this vulnerability.
A vulnerability in Common Internet Filesystem (CIFS) code in the Clientless SSL VPN functionality of Cisco ASA Software, Major Releases 9.0-9.6, could allow an authenticated, remote attacker to cause a heap overflow. The vulnerability is due to insufficient validation of user supplied input. An attacker could exploit this vulnerability by sending a crafted URL to the affected system. An exploit could allow the remote attacker to cause a reload of the affected system or potentially execute code. Note: Only traffic directed to the affected system can be used to exploit this vulnerability. This vulnerability affects systems configured in routed firewall mode only and in single or multiple context mode. This vulnerability can be triggered by IPv4 or IPv6 traffic. A valid TCP connection is needed to perform the attack. The attacker needs to have valid credentials to log in to the Clientless SSL VPN portal. Vulnerable Cisco ASA Software running on the following products may be affected by this vulnerability: Cisco ASA 5500 Series Adaptive Security Appliances, Cisco ASA 5500-X Series Next-Generation Firewalls, Cisco Adaptive Security Virtual Appliance (ASAv), Cisco ASA for Firepower 9300 Series, Cisco ASA for Firepower 4100 Series. Cisco Bug IDs: CSCvc23838.
A vulnerability in the command-line interface (CLI) parser of Cisco ASA software could allow an authenticated, local attacker to create a denial-of-service (DoS) condition or potentially execute code.
A buffer overflow vulnerability in the Simple Network Management Protocol (SNMP) code of Cisco ASA software could allow an attacker to cause a reload of the affected system or to remotely execute code.
The phone-proxy implementation in Cisco Adaptive Security Appliance (ASA) Software 9.0.3.6 and earlier does not properly validate X.509 certificates, which allows remote attackers to cause a denial of service (connection-database corruption) via an invalid entry, aka Bug ID CSCui33299.
Cisco Adaptive Security Appliances (ASA) devices with software 7.x before 7.2(5.10), 8.0 before 8.0(5.28), 8.1 and 8.2 before 8.2(5.35), 8.3 before 8.3(2.34), 8.4 before 8.4(4.11), 8.6 before 8.6(1.10), and 8.7 before 8.7(1.3), and Cisco Firewall Services Module (FWSM) software 3.1 and 3.2 before 3.2(24.1) and 4.0 and 4.1 before 4.1(11.1), allow remote attackers to cause a denial of service (device reload) via a crafted IKEv1 message, aka Bug IDs CSCub85692 and CSCud20267.
The auto-update implementation in Cisco Adaptive Security Appliance (ASA) Software 9.0.3.6 and earlier allows remote attackers to cause a denial of service (device reload) via crafted update data, aka Bug ID CSCui33308.
The IPv6 implementation in Cisco Adaptive Security Appliance (ASA) Software 9.1.3 and earlier, when NAT64 or NAT66 is enabled, does not properly process NAT rules, which allows remote attackers to cause a denial of service (device reload) via crafted packets, aka Bug ID CSCue34342.
Cisco Adaptive Security Appliances (ASA) devices with software 7.x before 7.2(5.10), 8.0 before 8.0(5.31), 8.1 and 8.2 before 8.2(5.38), 8.3 before 8.3(2.37), 8.4 before 8.4(5), 8.5 before 8.5(1.17), 8.6 before 8.6(1.10), and 8.7 before 8.7(1.3) allow remote attackers to cause a denial of service (device reload) via a crafted certificate, aka Bug ID CSCuc72408.
The authentication-proxy implementation on Cisco Adaptive Security Appliances (ASA) devices with software 7.x before 7.2(5.10), 8.0 before 8.0(5.31), 8.1 and 8.2 before 8.2(5.38), 8.3 before 8.3(2.37), 8.4 before 8.4(5.3), 8.5 and 8.6 before 8.6(1.10), 8.7 before 8.7(1.4), 9.0 before 9.0(1.1), and 9.1 before 9.1(1.2) allows remote attackers to cause a denial of service (device reload) via a crafted URL, aka Bug ID CSCud16590.
The NAT process on Cisco Adaptive Security Appliances (ASA) devices allows remote attackers to cause a denial of service (connections-table memory consumption) via crafted packets, aka Bug ID CSCue46386.
The platform-sw component on Cisco Adaptive Security Appliances (ASA) 5500 series devices with software 8.2 before 8.2(5.3), 8.3 before 8.3(2.20), and 8.4 before 8.4(2.1) does not properly handle non-ASCII characters in an interface description, which allows local users to cause a denial of service (reload without configuration) via a crafted description, aka Bug ID CSCtq50523.
Cisco Adaptive Security Appliances (ASA) 5500 series devices with software before 8.2(3) allow remote attackers to cause a denial of service (ASDM syslog outage) via a long URL, aka Bug IDs CSCsm11264 and CSCtb92911.
Unspecified vulnerability on Cisco Adaptive Security Appliances (ASA) 5500 series devices with software before 8.3(2) allows remote attackers to cause a denial of service (device crash) via a large number of LAN-to-LAN (aka L2L) IPsec sessions, aka Bug ID CSCth36592.
Cisco Adaptive Security Appliances (ASA) 5500 series devices with software before 8.3(2) do not properly preserve ACL behavior after a migration, which allows remote attackers to bypass intended access restrictions via an unspecified type of network traffic that had previously been denied, aka Bug ID CSCte46460.
The Mobile User Security (MUS) service on Cisco Adaptive Security Appliances (ASA) 5500 series devices with software before 8.3(2) does not properly authenticate HTTP requests from a Web Security appliance (WSA), which might allow remote attackers to obtain sensitive information via a HEAD request, aka Bug ID CSCte53635.
Unspecified vulnerability on Cisco Adaptive Security Appliances (ASA) 5500 series devices with software before 8.3(2) allows remote attackers to cause a denial of service (device crash) via multicast traffic, aka Bug IDs CSCtg61810 and CSCtg69742.
Unspecified vulnerability in the SIP inspection feature on Cisco Adaptive Security Appliances (ASA) 5500 series devices with software before 8.3(2) allows remote attackers to cause a denial of service (device crash) by making many SIP calls, aka Bug ID CSCte20030.
Memory leak on Cisco Adaptive Security Appliances (ASA) 5500 series devices with software before 8.2(3) allows remote attackers to cause a denial of service (memory consumption) by making multiple incorrect LDAP authentication attempts, aka Bug ID CSCtf29867.
Cisco Adaptive Security Appliances (ASA) 5500 series devices with software before 8.2(3) do not properly handle Online Certificate Status Protocol (OCSP) connection failures, which allows remote OCSP responders to cause a denial of service (TCP socket exhaustion) by rejecting connection attempts, aka Bug ID CSCsz36816.
Cisco Adaptive Security Appliances (ASA) 5500 series devices with software 8.2(3) and earlier allow remote attackers to cause a denial of service (block exhaustion) via EIGRP traffic that triggers an EIGRP multicast storm, aka Bug ID CSCtf20269.
The Neighbor Discovery (ND) protocol implementation in the IPv6 stack on Cisco Adaptive Security Appliances (ASA) 5500 series devices with software 8.2(3) and earlier, and Cisco PIX Security Appliances devices, allows remote attackers to cause a denial of service (CPU consumption and device hang) by sending many Router Advertisement (RA) messages with different source addresses, as demonstrated by the floodrouter6 program in the thc-ipv6 package, aka Bug ID CSCti24526.
Cisco Adaptive Security Appliances (ASA) 5500 series devices with software 8.2(4) and earlier allow remote attackers to cause a denial of service via a flood of packets, aka Bug ID CSCtg06316.
Cisco Adaptive Security Appliances (ASA) 5500 series devices with software before 8.2(3) permit packets to pass before the configuration has been loaded, which might allow remote attackers to bypass intended access restrictions by sending network traffic during device startup, aka Bug ID CSCsy86769.
emWEB on Cisco Adaptive Security Appliances (ASA) 5500 series devices with software before 8.2(3) allows remote attackers to cause a denial of service (daemon crash) via a request for a document whose name contains space characters, aka Bug ID CSCsy08416.
The WebVPN implementation on Cisco Adaptive Security Appliances (ASA) 5500 series devices with software before 8.2(3) permits the viewing of CIFS shares even when CIFS file browsing has been disabled, which allows remote authenticated users to bypass intended access restrictions via CIFS requests, aka Bug ID CSCsz80777.
Unspecified vulnerability on Cisco Adaptive Security Appliances (ASA) 5500 series devices with software before 8.2(3) allows remote attackers to bypass SMTP inspection via vectors involving a prepended space character, aka Bug ID CSCte14901.
Cisco Adaptive Security Appliances (ASA) 5500 series devices with software before 8.2(3) do not properly determine the interfaces for which TELNET connections should be permitted, which allows remote authenticated users to bypass intended access restrictions via vectors involving the "lowest security level interface," aka Bug ID CSCsv40504.
Unspecified vulnerability on Cisco Adaptive Security Appliances (ASA) 5500 series devices with software 8.2(4) and earlier allows remote attackers to cause a denial of service (block exhaustion) via multicast traffic, aka Bug ID CSCtg63992.
Unspecified vulnerability on Cisco Adaptive Security Appliances (ASA) 5500 series devices with software before 8.2(3) allows remote authenticated users to cause a denial of service (device crash) via a high volume of IPsec traffic, aka Bug ID CSCsx52748.