Full_Name: Mattias Andersson Version: 2.4.25 OS: Linux URL: ftp://ftp.openldap.org/incoming/ Submission from: (NULL) (83.182.107.220)
I have configured a proxy server using both the relay backend and the translucent overlay:
backend hdb backend relay
database hdb directory /var/lib/ldap suffix "dc=foo,dc=example,dc=com" rootdn "cn=admin,dc=foo,dc=example,dc=com" rootpw secret index objectClass eq
database relay suffix "dc=example,dc=com" overlay rwm rwm-suffixmassage "dc=foo,dc=example,dc=com" overlay translucent uri ldap://ldap.example.com
This configuration makes it possible for me to override attributes in the remote ldap directory and at the same time extend the local directory with new entries. This has been tested and works for authorization in a linux environment.
If I issue an LDAP search query, as follows,
ldapsearch -x -b dc=chalmers,dc=se -s base "(objectClass=*)" 1.1
it will yield the following debug output:
slapd starting conn=1000 fd=11 ACCEPT from IP=127.0.0.1:36838 (IP=0.0.0.0:389) conn=1000 op=0 BIND dn="" method=128 conn=1000 op=0 RESULT tag=97 err=0 text= conn=1000 op=1 SRCH base="dc=example,dc=com" scope=0 deref=0 filter="(objectClass=*)" conn=1000 op=1 SRCH attr=1.1 conn=1000 op=1: back-relay for DN="dc=example,dc=com" would call self. conn=1000 op=1 SEARCH RESULT tag=101 err=0 nentries=1 text= conn=1000 op=2 UNBIND conn=1000 fd=11 closed
However, if I query the server using the Softerra LDAP Administrator software (Windows), the slapd daemon crashes with an assertion error:
slapd starting conn=1000 fd=11 ACCEPT from IP=11.22.33.44:54752 (IP=0.0.0.0:389) conn=1000 op=0 BIND dn="" method=128 conn=1000 op=0 RESULT tag=97 err=0 text= conn=1000 op=1 SRCH base="dc=example,dc=com" scope=0 deref=0 filter="(objectClass=*)" conn=1000 op=1 SRCH attr=1.1 conn=1000 op=1: back-relay for DN="dc=example,dc=com" would call self. slapd: /build/buildd/openldap-2.4.25/servers/slapd/attr.c:236: attr_dup2: Assertion `j < i' failed. Aborted
This is a security vulnerability, since it would be enough to send an LDAP query to take down the server.
Mattias