It appears that Active Directory (and presumably LDAP) authentication fails if the user is a member of a group with special characters in the name. Realistically, retrieveUser fails which makes it look like an authentication issue. To resolve this, the DN of the group needs to be properly escaped before calling context.getAttributes(dn). This is probably related to the incomplete fix applied in JENKINS-3249 (https://issues.jenkins-ci.org/browse/JENKINS-3249).

The group that is failing is one we use to test our own LDAP code. It is named:
test,+"\<>;=/role

Here is the log information related to the authentication failure (with identifying data replaced):
Feb 27, 2012 11:43:13 AM hudson.plugins.active_directory.ActiveDirectoryUnixAuthenticationProvider retrieveUser
WARNING: Exhausted all configured domains and could not authenticat against any.

Feb 27, 2012 11:43:13 AM hudson.plugins.active_directory.ActiveDirectoryUnixAuthenticationProvider retrieveUser
WARNING: Credential exception tying to authenticate against EXAMPLE.COM domain
org.acegisecurity.BadCredentialsException: Failed to retrieve user information for example.user; nested exception is javax.naming.InvalidNameException: "CN=test\,+\"\\\<\>\;\=/role,OU=Groups,DC=Example,DC=com": [LDAP: error code 34 - 0000208F: LdapErr: DSID-0C090709, comment: Error processing name, data 0, v1db0]; remaining name '"CN=test\,+\"\\\<\>\;\=/role,OU=Groups,DC=Example,DC=com"'
at hudson.plugins.active_directory.ActiveDirectoryUnixAuthenticationProvider.retrieveUser(ActiveDirectoryUnixAuthenticationProvider.java:180)
at hudson.plugins.active_directory.ActiveDirectoryUnixAuthenticationProvider.retrieveUser(ActiveDirectoryUnixAuthenticationProvider.java:116)
at hudson.plugins.active_directory.ActiveDirectoryUnixAuthenticationProvider.retrieveUser(ActiveDirectoryUnixAuthenticationProvider.java:83)
at org.acegisecurity.providers.dao.AbstractUserDetailsAuthenticationProvider.authenticate(AbstractUserDetailsAuthenticationProvider.java:119)
at org.acegisecurity.providers.ProviderManager.doAuthentication(ProviderManager.java:195)
at org.acegisecurity.AbstractAuthenticationManager.authenticate(AbstractAuthenticationManager.java:45)
at org.acegisecurity.ui.webapp.AuthenticationProcessingFilter.attemptAuthentication(AuthenticationProcessingFilter.java:71)
at org.acegisecurity.ui.AbstractProcessingFilter.doFilter(AbstractProcessingFilter.java:252)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
at org.acegisecurity.ui.basicauth.BasicProcessingFilter.doFilter(BasicProcessingFilter.java:173)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
at jenkins.security.ApiTokenFilter.doFilter(ApiTokenFilter.java:61)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
at org.acegisecurity.context.HttpSessionContextIntegrationFilter.doFilter(HttpSessionContextIntegrationFilter.java:249)
at hudson.security.HttpSessionContextIntegrationFilter2.doFilter(HttpSessionContextIntegrationFilter2.java:66)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
at hudson.security.ChainedServletFilter.doFilter(ChainedServletFilter.java:76)
at hudson.security.HudsonFilter.doFilter(HudsonFilter.java:164)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at hudson.util.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:81)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:240)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:164)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:462)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:164)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:562)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:395)
at org.apache.coyote.ajp.AjpProcessor.process(AjpProcessor.java:301)
at org.apache.coyote.ajp.AjpProtocol$AjpConnectionHandler.process(AjpProtocol.java:183)
at org.apache.coyote.ajp.AjpProtocol$AjpConnectionHandler.process(AjpProtocol.java:169)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:302)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:662)
Caused by: javax.naming.InvalidNameException: "CN=test\,+\"\\\<\>\;\=/role,OU=Groups,DC=Example,DC=com": [LDAP: error code 34 - 0000208F: LdapErr: DSID-0C090709, comment: Error processing name, data 0, v1db0]; remaining name '"CN=test\,+\"\\\<\>\;\=/role,OU=Groups,DC=Example,DC=com"'
at com.sun.jndi.ldap.LdapCtx.processReturnCode(LdapCtx.java:2979)
at com.sun.jndi.ldap.LdapCtx.processReturnCode(LdapCtx.java:2794)
at com.sun.jndi.ldap.LdapCtx.c_getAttributes(LdapCtx.java:1309)
at com.sun.jndi.toolkit.ctx.ComponentDirContext.p_getAttributes(ComponentDirContext.java:213)
at com.sun.jndi.toolkit.ctx.PartialCompositeDirContext.getAttributes(PartialCompositeDirContext.java:121)
at com.sun.jndi.toolkit.ctx.PartialCompositeDirContext.getAttributes(PartialCompositeDirContext.java:109)
at hudson.plugins.active_directory.ActiveDirectoryUnixAuthenticationProvider.resolveGroups(ActiveDirectoryUnixAuthenticationProvider.java:223)
at hudson.plugins.active_directory.ActiveDirectoryUnixAuthenticationProvider.retrieveUser(ActiveDirectoryUnixAuthenticationProvider.java:172)
... 37 more

Feb 27, 2012 11:43:13 AM hudson.plugins.active_directory.ActiveDirectoryUnixAuthenticationProvider retrieveUser
WARNING: Failed to retrieve user information for example.user
javax.naming.InvalidNameException: "CN=test\,+\"\\\<\>\;\=/role,OU=Groups,DC=Example,DC=com": [LDAP: error code 34 - 0000208F: LdapErr: DSID-0C090709, comment: Error processing name, data 0, v1db0]; remaining name '"CN=test\,+\"\\\<\>\;\=/role,OU=Groups,DC=Example,DC=com"'
at com.sun.jndi.ldap.LdapCtx.processReturnCode(LdapCtx.java:2979)
at com.sun.jndi.ldap.LdapCtx.processReturnCode(LdapCtx.java:2794)
at com.sun.jndi.ldap.LdapCtx.c_getAttributes(LdapCtx.java:1309)
at com.sun.jndi.toolkit.ctx.ComponentDirContext.p_getAttributes(ComponentDirContext.java:213)
at com.sun.jndi.toolkit.ctx.PartialCompositeDirContext.getAttributes(PartialCompositeDirContext.java:121)
at com.sun.jndi.toolkit.ctx.PartialCompositeDirContext.getAttributes(PartialCompositeDirContext.java:109)
at hudson.plugins.active_directory.ActiveDirectoryUnixAuthenticationProvider.resolveGroups(ActiveDirectoryUnixAuthenticationProvider.java:223)
at hudson.plugins.active_directory.ActiveDirectoryUnixAuthenticationProvider.retrieveUser(ActiveDirectoryUnixAuthenticationProvider.java:172)
at hudson.plugins.active_directory.ActiveDirectoryUnixAuthenticationProvider.retrieveUser(ActiveDirectoryUnixAuthenticationProvider.java:116)
at hudson.plugins.active_directory.ActiveDirectoryUnixAuthenticationProvider.retrieveUser(ActiveDirectoryUnixAuthenticationProvider.java:83)
at org.acegisecurity.providers.dao.AbstractUserDetailsAuthenticationProvider.authenticate(AbstractUserDetailsAuthenticationProvider.java:119)
at org.acegisecurity.providers.ProviderManager.doAuthentication(ProviderManager.java:195)
at org.acegisecurity.AbstractAuthenticationManager.authenticate(AbstractAuthenticationManager.java:45)
at org.acegisecurity.ui.webapp.AuthenticationProcessingFilter.attemptAuthentication(AuthenticationProcessingFilter.java:71)
at org.acegisecurity.ui.AbstractProcessingFilter.doFilter(AbstractProcessingFilter.java:252)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
at org.acegisecurity.ui.basicauth.BasicProcessingFilter.doFilter(BasicProcessingFilter.java:173)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
at jenkins.security.ApiTokenFilter.doFilter(ApiTokenFilter.java:61)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
at org.acegisecurity.context.HttpSessionContextIntegrationFilter.doFilter(HttpSessionContextIntegrationFilter.java:249)
at hudson.security.HttpSessionContextIntegrationFilter2.doFilter(HttpSessionContextIntegrationFilter2.java:66)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
at hudson.security.ChainedServletFilter.doFilter(ChainedServletFilter.java:76)
at hudson.security.HudsonFilter.doFilter(HudsonFilter.java:164)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at hudson.util.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:81)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:240)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:164)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:462)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:164)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:562)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:395)
at org.apache.coyote.ajp.AjpProcessor.process(AjpProcessor.java:301)
at org.apache.coyote.ajp.AjpProtocol$AjpConnectionHandler.process(AjpProtocol.java:183)
at org.apache.coyote.ajp.AjpProtocol$AjpConnectionHandler.process(AjpProtocol.java:169)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:302)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:662)

Feb 27, 2012 11:43:13 AM hudson.plugins.active_directory.ActiveDirectoryUnixAuthenticationProvider resolveGroups
FINE: Example User is a member of CN=test\,+\"\\\<\>\;\=/role,OU=Groups,DC=Example,DC=com

Feb 27, 2012 11:43:13 AM hudson.plugins.active_directory.ActiveDirectoryUnixAuthenticationProvider resolveGroups
FINE: Example User is a member of CN=Working Example,OU=Groups,DC=Example,DC=com

Feb 27, 2012 11:43:13 AM hudson.plugins.active_directory.ActiveDirectoryUnixAuthenticationProvider retrieveUser
FINE: Failed to find example.user in userPrincipalName. Trying sAMAccountName

Feb 27, 2012 11:43:13 AM hudson.plugins.active_directory.ActiveDirectorySecurityRealm$DesciprotrImpl bind
FINE: Bound to b-ad-01.example.com:3269

Feb 27, 2012 11:43:13 AM hudson.plugins.active_directory.ActiveDirectorySecurityRealm$DesciprotrImpl bind
WARNING: Failed to bind to 10.10.10.10:389
javax.naming.CommunicationException: simple bind failed: 10.10.10.10:389 [Root exception is java.net.SocketException: Connection reset]
at com.sun.jndi.ldap.LdapClient.authenticate(LdapClient.java:197)
at com.sun.jndi.ldap.LdapCtx.connect(LdapCtx.java:2694)
at com.sun.jndi.ldap.LdapCtx.<init>(LdapCtx.java:293)
at com.sun.jndi.ldap.LdapCtxFactory.getUsingURL(LdapCtxFactory.java:175)
at com.sun.jndi.ldap.LdapCtxFactory.getLdapCtxInstance(LdapCtxFactory.java:134)
at hudson.plugins.active_directory.ActiveDirectorySecurityRealm$DesciprotrImpl.bind(ActiveDirectorySecurityRealm.java:293)
at hudson.plugins.active_directory.ActiveDirectoryUnixAuthenticationProvider.retrieveUser(ActiveDirectoryUnixAuthenticationProvider.java:142)
at hudson.plugins.active_directory.ActiveDirectoryUnixAuthenticationProvider.retrieveUser(ActiveDirectoryUnixAuthenticationProvider.java:116)
at hudson.plugins.active_directory.ActiveDirectoryUnixAuthenticationProvider.retrieveUser(ActiveDirectoryUnixAuthenticationProvider.java:83)
at org.acegisecurity.providers.dao.AbstractUserDetailsAuthenticationProvider.authenticate(AbstractUserDetailsAuthenticationProvider.java:119)
at org.acegisecurity.providers.ProviderManager.doAuthentication(ProviderManager.java:195)
at org.acegisecurity.AbstractAuthenticationManager.authenticate(AbstractAuthenticationManager.java:45)
at org.acegisecurity.ui.webapp.AuthenticationProcessingFilter.attemptAuthentication(AuthenticationProcessingFilter.java:71)
at org.acegisecurity.ui.AbstractProcessingFilter.doFilter(AbstractProcessingFilter.java:252)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
at org.acegisecurity.ui.basicauth.BasicProcessingFilter.doFilter(BasicProcessingFilter.java:173)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
at jenkins.security.ApiTokenFilter.doFilter(ApiTokenFilter.java:61)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
at org.acegisecurity.context.HttpSessionContextIntegrationFilter.doFilter(HttpSessionContextIntegrationFilter.java:249)
at hudson.security.HttpSessionContextIntegrationFilter2.doFilter(HttpSessionContextIntegrationFilter2.java:66)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
at hudson.security.ChainedServletFilter.doFilter(ChainedServletFilter.java:76)
at hudson.security.HudsonFilter.doFilter(HudsonFilter.java:164)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at hudson.util.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:81)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:240)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:164)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:462)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:164)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:562)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:395)
at org.apache.coyote.ajp.AjpProcessor.process(AjpProcessor.java:301)
at org.apache.coyote.ajp.AjpProtocol$AjpConnectionHandler.process(AjpProtocol.java:183)
at org.apache.coyote.ajp.AjpProtocol$AjpConnectionHandler.process(AjpProtocol.java:169)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:302)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:662)
Caused by: java.net.SocketException: Connection reset
at java.net.SocketInputStream.read(SocketInputStream.java:168)
at com.sun.net.ssl.internal.ssl.InputRecord.readFully(InputRecord.java:293)
at com.sun.net.ssl.internal.ssl.InputRecord.read(InputRecord.java:331)
at com.sun.net.ssl.internal.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:798)
at com.sun.net.ssl.internal.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1138)
at com.sun.net.ssl.internal.ssl.SSLSocketImpl.writeRecord(SSLSocketImpl.java:632)
at com.sun.net.ssl.internal.ssl.AppOutputStream.write(AppOutputStream.java:59)
at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:65)
at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:123)
at com.sun.jndi.ldap.Connection.writeRequest(Connection.java:396)
at com.sun.jndi.ldap.LdapClient.ldapBind(LdapClient.java:334)
at com.sun.jndi.ldap.LdapClient.authenticate(LdapClient.java:192)
... 43 more

Feb 27, 2012 11:43:13 AM hudson.plugins.active_directory.ActiveDirectorySecurityRealm$DesciprotrImpl obtainLDAPServer
FINE: _gc._tcp.EXAMPLE.COM resolved to [b-ad-01.example.com:3269, b-ad-01.example.com:3269, c-ad-01.example.com:3269, v-ad-01.example.com:3269, j-ad-01.example.com:3269, s-ms-ad-01.example.com:3269, b-ms-ad-01.example.com:3269]

Feb 27, 2012 11:43:13 AM hudson.plugins.active_directory.ActiveDirectorySecurityRealm$DesciprotrImpl obtainLDAPServer
FINE: Attempting to resolve _gc._tcp.EXAMPLE.COM to SRV record