Qualys Vulnerability R&D Lab has released new vulnerability checks in the Enterprise TruRisk Platform to protect organizations against 8 vulnerabilities that were fixed in 8 bulletins announced today by Samba. Customers can immediately audit their networks for these and other new vulnerabilities by accessing their Qualys subscription. Visit Qualys Security Blog to prioritize remediation.
Non-Qualys customers can audit their network for these and other vulnerabilities by signing up for a Qualys Free Trial, or by trying Qualys Community Edition.
Samba has released 8 security bulletins to fix newly discovered flaws in their software. Qualys has released the following checks for these new vulnerabilities:
Badlock, a crucial security bug in Windows and Samba was disclosed which allows attackers to perform SAMR and LSA man in the middle attacks. A man in the middle can intercept any DCERPC traffic between a client and a server in order to impersonate the client and get the same privileges as the authenticated user account. This is most problematic against active directory domain controllers.
Versions of Samba from 3.6.0 to 4.4.0 inclusive are vulnerable to denial of service attacks (crashes and high cpu consumption) in the DCE-RPC client and server implementations. In addition, errors in validation of the DCE-RPC packets can lead to a downgrade of a secure connection to an insecure one.
The NETLOGON service in Microsoft Windows Server 2003 SP2, Windows Server 2008 SP2 and R2 SP1, and Windows Server 2012 Gold and R2, when a Domain Controller is configured, allows remote attackers to spoof the computer name of a secure channel's endpoint, and obtain sensitive session information, by running a crafted application and leveraging the ability to sniff network traffic, aka "NETLOGON Spoofing Vulnerability".
A man in the middle is able to downgrade LDAP connections to no integrity protection. It's possible to attack client and server with this.
Man in the middle attacks are possible for client triggered LDAP connections (with ldaps://) and ncacn_http connections (with https://).
Due to a bug Samba doesn't enforce required smb signing, even if explicitly configured. In addition the default for the active directory domain controller case was wrong.
The protection of DCERPC communication over ncacn_np (which is the default for most the file server related protocols) is inherited from the underlying SMB connection. Samba doesn't enforce SMB signing for this kind of SMB connections by default, which makes man in the middle attacks possible.
Affected versions of Samba are:
3.6.x,4.0.x,4.1.x,4.2.0-4.2.9,4.3.0-4.3.6,4.4.0
Patches:
The following are links for downloading patches to fix these vulnerabilities:
Samba Badlock Vulnerability Samba 4.2.9
Samba Badlock Vulnerability Samba 4.3.6
Samba Badlock Vulnerability Samba 4.4.0
The following packages have been upgraded to a newer upstream version: Samba (4.2.10). Refer to the Release Notes listed in the References section for a complete list of changes.
Security Fix(es):
* Multiple flaws were found in Samba's DCE/RPC protocol implementation. A remote, authenticated attacker could use these flaws to cause a denial of service against the Samba server (high CPU load or a crash) or, possibly, execute arbitrary code with the permissions of the user running Samba (root). This flaw could also be used to downgrade a secure DCE/RPC connection by a man-in-the-middle attacker taking control of an Active Directory (AD) object and compromising the security of a Samba Active Directory Domain Controller (DC). (CVE-2015-5370)
Note: While Samba packages as shipped in Red Hat Enterprise Linux do not support running Samba as an AD DC, this flaw applies to all roles Samba implements.
* A protocol flaw, publicly referred to as Badlock, was found in the Security Account Manager Remote Protocol (MS-SAMR) and the Local Security Authority (Domain Policy) Remote Protocol (MS-LSAD). Any authenticated DCE/RPC connection that a client initiates against a server could be used by a man-in-the-middle attacker to impersonate the authenticated user against the SAMR or LSA service on the server. As a result, the attacker would be able to get read/write access to the Security Account Manager database, and use this to reveal all passwords or any other potentially sensitive information in that database. (CVE-2016-2118)
* Several flaws were found in Samba's implementation of NTLMSSP authentication. An unauthenticated, man-in-the-middle attacker could use this flaw to clear the encryption and integrity flags of a connection, causing data to be transmitted in plain text. The attacker could also force the client or server into sending data in plain text even if encryption was explicitly requested for that connection. (CVE-2016-2110)
* It was discovered that Samba configured as a Domain Controller would establish a secure communication channel with a machine using a spoofed computer name. A remote attacker able to observe network traffic could use this flaw to obtain session-related information about the spoofed machine. (CVE-2016-2111)
* It was found that Samba's LDAP implementation did not enforce integrity protection for LDAP connections. A man-in-the-middle attacker could use this flaw to downgrade LDAP connections to use no integrity protection, allowing them to hijack such connections. (CVE-2016-2112)
* It was found that Samba did not validate SSL/TLS certificates in certain connections. A man-in-the-middle attacker could use this flaw to spoof a Samba server using a specially crafted SSL/TLS certificate. (CVE-2016-2113)
* It was discovered that Samba did not enforce Server Message Block (SMB) signing for clients using the SMB1 protocol. A man-in-the-middle attacker could use this flaw to modify traffic between a client and a server. (CVE-2016-2114)
* It was found that Samba did not enable integrity protection for IPC traffic by default. A man-in-the-middle attacker could use this flaw to view and modify the data sent between a Samba server and a client. (CVE-2016-2115)
Refer to Red Hat security advisory RHSA-2016-0618 to address this issue and obtain more information.
Patches:
The following are links for downloading patches to fix these vulnerabilities:
RHSA-2016-0618 Red Hat Enterprise Linux
A protocol flaw, publicly referred to as Badlock, was found in the Security Account Manager Remote Protocol (MS-SAMR) and the Local Security Authority (Domain Policy) Remote Protocol (MS-LSAD). Any authenticated DCE/RPC connection that a client initiates against a server could be used by a man-in-the-middle attacker to impersonate the authenticated user against the SAMR or LSA service on the server. As a result, the attacker would be able to get read/write access to the Security Account Manager database, and use this to reveal all passwords or any other potentially sensitive information in that database. (CVE-2016-2118)
Several flaws were found in Samba's implementation of NTLMSSP authentication. An unauthenticated, man-in-the-middle attacker could use this flaw to clear the encryption and integrity flags of a connection, causing data to be transmitted in plain text. The attacker could also force the client or server into sending data in plain text even if encryption was explicitly requested for that connection. (CVE-2016-2110)
It was discovered that Samba configured as a Domain Controller would establish a secure communication channel with a machine using a spoofed computer name. A remote attacker able to observe network traffic could use this flaw to obtain session-related information about the spoofed machine. (CVE-2016-2111).
It was found that Samba's LDAP implementation did not enforce integrity protection for LDAP connections. A man-in-the-middle attacker could use this flaw to downgrade LDAP connections to use no integrity protection, allowing them to hijack such connections. (CVE-2016-2112)
It was found that Samba did not validate SSL/TLS certificates in certain connections. A man-in-the-middle attacker could use this flaw to spoof a Samba server using a specially crafted SSL/TLS certificate. (CVE-2016-2113)
It was discovered that Samba did not enforce Server Message Block (SMB) signing for clients using the SMB1 protocol. A man-in-the-middle attacker could use this flaw to modify traffic between a client and a server. (CVE-2016-2114)
It was found that Samba did not enable integrity protection for IPC traffic by default. A man-in-the-middle attacker could use this flaw to view and modify the data sent between a Samba server and a client. (CVE-2016-2115)
Refer to Red Hat security advisory RHSA-2016-0620 to address this issue and obtain more information.
Patches:
The following are links for downloading patches to fix these vulnerabilities:
RHSA-2016-0620 Red Hat Enterprise Linux
Security Fix(es):
* Multiple flaws were found in Samba's DCE/RPC protocol implementation. A remote, authenticated attacker could use these flaws to cause a denial of service against the Samba server (high CPU load or a crash) or, possibly, execute arbitrary code with the permissions of the user running Samba (root). This flaw could also be used to downgrade a secure DCE/RPC connection by a man-in-the-middle attacker taking control of an Active Directory (AD) object and compromising the security of a Samba Active Directory Domain Controller (DC). (CVE-2015-5370)
Note: While Samba packages as shipped in Red Hat Enterprise Linux do not support running Samba as an AD DC, this flaw applies to all roles Samba implements.
* A protocol flaw, publicly referred to as Badlock, was found in the Security Account Manager Remote Protocol (MS-SAMR) and the Local Security Authority (Domain Policy) Remote Protocol (MS-LSAD). Any authenticated DCE/RPC connection that a client initiates against a server could be used by a man-in-the-middle attacker to impersonate the authenticated user against the SAMR or LSA service on the server. As a result, the attacker would be able to get read/write access to the Security Account Manager database, and use this to reveal all passwords or any other potentially sensitive information in that database. (CVE-2016-2118)
* Several flaws were found in Samba's implementation of NTLMSSP authentication. An unauthenticated, man-in-the-middle attacker could use this flaw to clear the encryption and integrity flags of a connection, causing data to be transmitted in plain text. The attacker could also force the client or server into sending data in plain text even if encryption was explicitly requested for that connection. (CVE-2016-2110)
* It was discovered that Samba configured as a Domain Controller would establish a secure communication channel with a machine using a spoofed computer name. A remote attacker able to observe network traffic could use this flaw to obtain session-related information about the spoofed machine. (CVE-2016-2111)
* It was found that Samba's LDAP implementation did not enforce integrity protection for LDAP connections. A man-in-the-middle attacker could use this flaw to downgrade LDAP connections to use no integrity protection, allowing them to hijack such connections. (CVE-2016-2112)
* It was found that Samba did not enable integrity protection for IPC traffic by default. A man-in-the-middle attacker could use this flaw to view and modify the data sent between a Samba server and a client. (CVE-2016-2115)
Refer to Red Hat security advisory RHSA-2016-0619 to address this issue and obtain more information.
Patches:
The following are links for downloading patches to fix these vulnerabilities:
RHSA-2016-0619 Red Hat Enterprise Linux
The following packages have been upgraded to a newer upstream version: Samba (4.2.10). Refer to the Release Notes listed in the References section for a complete list of changes.
Security Fix(es):
* Multiple flaws were found in Samba's DCE/RPC protocol implementation. A remote, authenticated attacker could use these flaws to cause a denial of service against the Samba server (high CPU load or a crash) or, possibly, execute arbitrary code with the permissions of the user running Samba (root). This flaw could also be used to downgrade a secure DCE/RPC connection by a man-in-the-middle attacker taking control of an Active Directory (AD) object and compromising the security of a Samba Active Directory Domain Controller (DC). (CVE-2015-5370)
Note: While Samba packages as shipped in Red Hat Enterprise Linux do not support running Samba as an AD DC, this flaw applies to all roles Samba implements.
* A protocol flaw, publicly referred to as Badlock, was found in the Security Account Manager Remote Protocol (MS-SAMR) and the Local Security Authority (Domain Policy) Remote Protocol (MS-LSAD). Any authenticated DCE/RPC connection that a client initiates against a server could be used by a man-in-the-middle attacker to impersonate the authenticated user against the SAMR or LSA service on the server. As a result, the attacker would be able to get read/write access to the Security Account Manager database, and use this to reveal all passwords or any other potentially sensitive information in that database. (CVE-2016-2118)
* Several flaws were found in Samba's implementation of NTLMSSP authentication. An unauthenticated, man-in-the-middle attacker could use this flaw to clear the encryption and integrity flags of a connection, causing data to be transmitted in plain text. The attacker could also force the client or server into sending data in plain text even if encryption was explicitly requested for that connection. (CVE-2016-2110)
* It was discovered that Samba configured as a Domain Controller would establish a secure communication channel with a machine using a spoofed computer name. A remote attacker able to observe network traffic could use this flaw to obtain session-related information about the spoofed machine. (CVE-2016-2111)
* It was found that Samba's LDAP implementation did not enforce integrity protection for LDAP connections. A man-in-the-middle attacker could use this flaw to downgrade LDAP connections to use no integrity protection, allowing them to hijack such connections. (CVE-2016-2112)
* It was found that Samba did not validate SSL/TLS certificates in certain connections. A man-in-the-middle attacker could use this flaw to spoof a Samba server using a specially crafted SSL/TLS certificate. (CVE-2016-2113)
* It was discovered that Samba did not enforce Server Message Block (SMB) signing for clients using the SMB1 protocol. A man-in-the-middle attacker could use this flaw to modify traffic between a client and a server. (CVE-2016-2114)
* It was found that Samba did not enable integrity protection for IPC traffic by default. A man-in-the-middle attacker could use this flaw to view and modify the data sent between a Samba server and a client. (CVE-2016-2115)
Refer to Red Hat security advisory RHSA-2016-0612 to address this issue and obtain more information.
Patches:
The following are links for downloading patches to fix these vulnerabilities:
RHSA-2016-0612 Red Hat Enterprise Linux 6, 7
Security Fix(es):
* Multiple flaws were found in Samba's DCE/RPC protocol implementation. A remote, authenticated attacker could use these flaws to cause a denial of service against the Samba server (high CPU load or a crash) or, possibly, execute arbitrary code with the permissions of the user running Samba (root). This flaw could also be used to downgrade a secure DCE/RPC connection by a man-in-the-middle attacker taking control of an Active Directory (AD) object and compromising the security of a Samba Active Directory Domain Controller (DC). (CVE-2015-5370)
Note: While Samba packages as shipped in Red Hat Enterprise Linux do not support running Samba as an AD DC, this flaw applies to all roles Samba implements.
* A protocol flaw, publicly referred to as Badlock, was found in the Security Account Manager Remote Protocol (MS-SAMR) and the Local Security Authority (Domain Policy) Remote Protocol (MS-LSAD). Any authenticated DCE/RPC connection that a client initiates against a server could be used by a man-in-the-middle attacker to impersonate the authenticated user against the SAMR or LSA service on the server. As a result, the attacker would be able to get read/write access to the Security Account Manager database, and use this to reveal all passwords or any other potentially sensitive information in that database. (CVE-2016-2118)
* It was discovered that Samba configured as a Domain Controller would establish a secure communication channel with a machine using a spoofed computer name. A remote attacker able to observe network traffic could use this flaw to obtain session-related information about the spoofed machine. (CVE-2016-2111)
* It was found that Samba's LDAP implementation did not enforce integrity protection for LDAP connections. A man-in-the-middle attacker could use this flaw to downgrade LDAP connections to use no integrity protection, allowing them to hijack such connections. (CVE-2016-2112)
* It was found that Samba did not enable integrity protection for IPC traffic by default. A man-in-the-middle attacker could use this flaw to view and modify the data sent between a Samba server and a client. (CVE-2016-2115)
Refer to Red Hat security advisory RHSA-2016-0611 to address this issue and obtain more information.
Patches:
The following are links for downloading patches to fix these vulnerabilities:
RHSA-2016-0611 Red Hat Enterprise Linux 6
Security Fix(es):
* A protocol flaw, publicly referred to as Badlock, was found in the Security Account Manager Remote Protocol (MS-SAMR) and the Local Security Authority (Domain Policy) Remote Protocol (MS-LSAD). Any authenticated DCE/RPC connection that a client initiates against a server could be used by a man-in-the-middle attacker to impersonate the authenticated user against the SAMR or LSA service on the server. As a result, the attacker would be able to get read/write access to the Security Account Manager database, and use this to reveal all passwords or any other potentially sensitive information in that database. (CVE-2016-2118)
* Several flaws were found in Samba's implementation of NTLMSSP authentication. An unauthenticated, man-in-the-middle attacker could use this flaw to clear the encryption and integrity flags of a connection, causing data to be transmitted in plain text. The attacker could also force the client or server into sending data in plain text even if encryption was explicitly requested for that connection. (CVE-2016-2110)
* It was discovered that Samba configured as a Domain Controller would establish a secure communication channel with a machine using a spoofed computer name. A remote attacker able to observe network traffic could use this flaw to obtain session-related information about the spoofed machine. (CVE-2016-2111)
* It was found that Samba's LDAP implementation did not enforce integrity protection for LDAP connections. A man-in-the-middle attacker could use this flaw to downgrade LDAP connections to use no integrity protection, allowing them to hijack such connections. (CVE-2016-2112)
* It was found that Samba did not enable integrity protection for IPC traffic by default. A man-in-the-middle attacker could use this flaw to view and modify the data sent between a Samba server and a client. (CVE-2016-2115)
Refer to Red Hat security advisory RHSA-2016-0621 to address this issue and obtain more information.
Patches:
The following are links for downloading patches to fix these vulnerabilities:
RHSA-2016-0621 Red Hat Enterprise Linux 5
Security Fix(es):
* Multiple flaws were found in Samba's DCE/RPC protocol implementation. A remote, authenticated attacker could use these flaws to cause a denial of service against the Samba server (high CPU load or a crash) or, possibly, execute arbitrary code with the permissions of the user running Samba (root). This flaw could also be used to downgrade a secure DCE/RPC connection by a man-in-the-middle attacker taking control of an Active Directory (AD) object and compromising the security of a Samba Active Directory Domain Controller (DC). (CVE-2015-5370)
Note: While Samba packages as shipped in Red Hat Enterprise Linux do not support running Samba as an AD DC, this flaw applies to all roles Samba implements.
* A protocol flaw, publicly referred to as Badlock, was found in the Security Account Manager Remote Protocol (MS-SAMR) and the Local Security Authority (Domain Policy) Remote Protocol (MS-LSAD). Any authenticated DCE/RPC connection that a client initiates against a server could be used by a man-in-the-middle attacker to impersonate the authenticated user against the SAMR or LSA service on the server. As a result, the attacker would be able to get read/write access to the Security Account Manager database, and use this to reveal all passwords or any other potentially sensitive information in that database. (CVE-2016-2118)
* Several flaws were found in Samba's implementation of NTLMSSP authentication. An unauthenticated, man-in-the-middle attacker could use this flaw to clear the encryption and integrity flags of a connection, causing data to be transmitted in plain text. The attacker could also force the client or server into sending data in plain text even if encryption was explicitly requested for that connection. (CVE-2016-2110)
* It was discovered that Samba configured as a Domain Controller would establish a secure communication channel with a machine using a spoofed computer name. A remote attacker able to observe network traffic could use this flaw to obtain session-related information about the spoofed machine. (CVE-2016-2111)
* It was found that Samba's LDAP implementation did not enforce integrity protection for LDAP connections. A man-in-the-middle attacker could use this flaw to downgrade LDAP connections to use no integrity protection, allowing them to hijack such connections. (CVE-2016-2112)
* It was found that Samba did not enable integrity protection for IPC traffic by default. A man-in-the-middle attacker could use this flaw to view and modify the data sent between a Samba server and a client. (CVE-2016-2115)
Refer to Red Hat security advisory RHSA-2016-0613 to address this issue and obtain more information.
Patches:
The following are links for downloading patches to fix these vulnerabilities:
RHSA-2016-0613 Red Hat Enterprise Linux 5
These new vulnerability checks are included in Qualys vulnerability signature 2.3.281-3. Each Qualys account is automatically updated with the latest vulnerability signatures as they become available. To view the vulnerability signature version in your account, from the Qualys Help menu, select the About tab.
To perform a selective vulnerability scan, configure a scan profile to use the following options:
In addition, prior to running a scan for these new vulnerabilities, you can estimate your exposure to these new threats by running the Risk Analysis Report, available from the Qualys Vulnerability Management Reports tab.
Platforms and Platform Identification
For more information, customers may contact Qualys Technical Support.
The Enterprise TruRisk Platform and its integrated suite of security and compliance applications provides organizations of all sizes with a global view of their security and compliance solutions, while drastically reducing their total cost of ownership. Qualys solutions include: continuous monitoring, vulnerability management, policy compliance, PCI compliance, security assessment questionnaire, web application scanning, web application firewall, malware detection and SECURE Seal for security testing of web sites.