An issue was discovered in the server in OpenLDAP before 2.4.48. When the server administrator delegates rootDN (database admin) privileges for certain databases but wants to maintain isolation (e.g., for multi-tenant deployments), slapd does not properly stop a rootDN from requesting authorization as an identity from another database during a SASL bind or with a proxyAuthz (RFC 4370) control. (It is not a common configuration to deploy a system where the server administrator and a DB administrator enjoy different levels of trust.)

An issue was discovered in OpenLDAP 2.x before 2.4.48. When using SASL authentication and session encryption, and relying on the SASL security layers in slapd access controls, it is possible to obtain access that would otherwise be denied via a simple bind for any identity covered in those ACLs. After the first SASL bind is completed, the sasl_ssf value is retained for all new non-SASL connections. Depending on the ACL configuration, this can affect different types of operations (searches, modifications, etc.). In other words, a successful authorization step completed by one user affects the authorization requirement for a different user.

contrib/slapd-modules/nops/nops.c in OpenLDAP through 2.4.45, when both the nops module and the memberof overlay are enabled, attempts to free a buffer that was allocated on the stack, which allows remote attackers to cause a denial of service (slapd crash) via a member MODDN operation.

slapd in OpenLDAP 2.4.45 and earlier creates a PID file after dropping privileges to a non-root account, which might allow local users to kill arbitrary processes by leveraging access to this non-root account for PID file modification before a root script executes a "kill `cat /pathname`" command, as demonstrated by openldap-initscript.

/usr/libexec/openldap/generate-server-cert.sh in openldap-servers sets weak permissions for the TLS certificate, which allows local users to obtain the TLS certificate by leveraging a race condition between the creation of the certificate, and the chmod to protect it.

servers/slapd/back-mdb/search.c in OpenLDAP through 2.4.44 is prone to a double free vulnerability. A user with access to search the directory can crash slapd by issuing a search including the Paged Results control with a page size of 0.

The nss_parse_ciphers function in libraries/libldap/tls_m.c in OpenLDAP does not properly parse OpenSSL-style multi-keyword mode cipher strings, which might cause a weaker than intended cipher to be used and allow remote attackers to have unspecified impact via unknown vectors.

The ber_get_next function in libraries/liblber/io.c in OpenLDAP 2.4.42 and earlier allows remote attackers to cause a denial of service (reachable assertion and application crash) via crafted BER data, as demonstrated by an attack against slapd.

The default slapd configuration in the Debian openldap package 2.4.23-3 through 2.4.39-1.1 allows remote authenticated users to modify the user's permissions and other user attributes via unspecified vectors.

Double free vulnerability in the get_vrFilter function in servers/slapd/filter.c in OpenLDAP 2.4.40 allows remote attackers to cause a denial of service (crash) via a crafted search query with a matched values control.