Samba contains a vulnerability that could allow an unauthenticated, remote attacker to execute arbitrary code on an affected system.
The vulnerability is due to improper handling of remote procedure call (RPC) requests by the affected software. An unauthenticated, remote attacker could exploit the vulnerability by sending a malicious request to the targeted system. If successful, the attacker could execute arbitrary code with root-level privileges.
Proof-of-concept code that demonstrates an exploit of this vulnerability is publicly available.
Samba has confirmed this vulnerability and released updated software.
Indicators of Compromise
Samba versions 3.6.3 and prior are vulnerable.
The vulnerability exists because the affected software improperly handles the NDR PULL DFS INFO3 user-supplied request. Similarly, the affected software also improperly handles requests such as NDR PULL LSA TrustDomainInfoControllers, NDR PULL SVCCTL StartServiceW, NDR PULL DFS EnumArray1, GetAliasMembership, SetInfoPolicy, lsa_LookupNames, ndr_ValidatePassword, or ReportEventW.
An unauthenticated, remote attacker could exploit this vulnerability by sending specially crafted requests to the vulnerable software. While processing these requests, the software uses a field for memory allocation and another field to write data to that allocation. However, the software fails to validate both fields, which could lead to a buffer overflow, corrupting memory. The attacker could take advantage of the buffer overflow to execute arbitrary code on the targeted system with root level privileges.
If an exploit is successful, the attacker could execute arbitrary code on the system with elevated privileges, possibly resulting in a complete system compromise.
The vendor report indicates that authentication is not required to exploit the vulnerability. However, to be able to send the RPC requests to the system, the attacker would need access to trusted, internal networks. This requirement may limit the likelihood of a successful exploit.
Administrators are advised to apply the appropriate updates.
Administrators are advised to implement an intrusion prevention system (IPS) or intrusion detection system (IDS) to help detect and prevent attacks that attempt to exploit this vulnerability.
Administrators are advised to monitor affected systems.
Samba has released a security advisory at the following link: CVE-2012-1182
Apple has released a security advisory at the following link: HT5281
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Cisco Multivendor Vulnerability Alerts respond to vulnerabilities identified in third-party vendors' products. These alerts contain information compiled from diverse sources and provide comprehensive technical descriptions, objective analytical assessments, workarounds and practical safeguards, and links to vendor advisories and patches.