MIT Kerberos 5 - any version

The telnet daemon (telnetd) in MIT krb5 before 1.6.1 allows remote attackers to bypass authentication and gain system access via a username beginning with a '-' character, a similar issue to CVE-2007-0882.

The kadm_ser_in function in (1) the Kerberos v4compatibility administration daemon (kadmind4) in the MIT Kerberos 5 (krb5) krb5-1.2.6 and earlier, (2) kadmind in KTH Kerberos 4 (eBones) before 1.2.1, and (3) kadmind in KTH Kerberos 5 (Heimdal) before 0.5.1 when compiled with Kerberos 4 support, does not properly verify the length field of a request, which allows remote attackers to execute arbitrary code via a buffer overflow attack.

The gssrpc__svcauth_gssapi function in the RPC library in MIT Kerberos 5 (krb5) 1.6.1 and earlier might allow remote attackers to execute arbitrary code via a zero-length RPC credential, which causes kadmind to free an uninitialized pointer during cleanup.

The asn1_decode_generaltime function in lib/krb5/asn.1/asn1_decode.c in the ASN.1 GeneralizedTime decoder in MIT Kerberos 5 (aka krb5) before 1.6.4 allows remote attackers to cause a denial of service (daemon crash) or possibly execute arbitrary code via vectors involving an invalid DER encoding that triggers a free of an uninitialized pointer.

Integer overflow in the svcauth_gss_get_principal function in lib/rpc/svc_auth_gss.c in MIT Kerberos 5 (krb5) allows remote attackers to have an unknown impact via a large length value for a GSS client name in an RPC request.

Double free vulnerability in the krb5_recvauth function in MIT Kerberos 5 (krb5) 1.4.1 and earlier allows remote attackers to execute arbitrary code via certain error conditions.

KDC in MIT Kerberos 5 (krb5kdc) does not set a global variable for some krb4 message types, which allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via crafted messages that trigger a NULL pointer dereference or double-free.

plugins/preauth/pkinit/pkinit_crypto_openssl.c in MIT Kerberos 5 (aka krb5) through 1.15.2 mishandles Distinguished Name (DN) fields, which allows remote attackers to execute arbitrary code or cause a denial of service (buffer overflow and application crash) in situations involving untrusted X.509 data, related to the get_matching_data and X509_NAME_oneline_ex functions. NOTE: this has security relevance only in use cases outside of the MIT Kerberos distribution, e.g., the use of get_matching_data in KDC certauth plugin code that is specific to Red Hat.

Double free vulnerabilities in error handling code in krb524d for MIT Kerberos 5 (krb5) 1.2.8 and earlier may allow remote attackers to execute arbitrary code.

The reply function in ftpd.c in the gssftp ftpd in MIT Kerberos 5 (krb5) does not initialize the length variable when auth_type has a certain value, which has unknown impact and remote authenticated attack vectors. NOTE: the original disclosure misidentifies the conditions under which the uninitialized variable is used. NOTE: the vendor disputes this issue, stating " The 'length' variable is only uninitialized if 'auth_type' is neither the 'KERBEROS_V4' nor 'GSSAPI'; this condition cannot occur in the unmodified source code.

In MIT Kerberos 5 (aka krb5) before 1.21.3, an attacker can cause invalid memory reads during GSS message token handling by sending message tokens with invalid length fields.

Stack-based buffer overflow in the krb5_klog_syslog function in the kadm5 library, as used by the Kerberos administration daemon (kadmind) and Key Distribution Center (KDC), in MIT krb5 before 1.6.1 allows remote authenticated users to execute arbitrary code and modify the Kerberos key database via crafted arguments, possibly involving certain format string specifiers.

Double free vulnerability in the GSS-API library (lib/gssapi/krb5/k5unseal.c), as used by the Kerberos administration daemon (kadmind) in MIT krb5 before 1.6.1, when used with the authentication method provided by the RPCSEC_GSS RPC library, allows remote authenticated users to execute arbitrary code and modify the Kerberos key database via a message with an "an invalid direction encoding".

Stack-based buffer overflow in the rename_principal_2_svc function in kadmind for MIT Kerberos 1.5.3, 1.6.1, and other versions allows remote authenticated users to execute arbitrary code via a crafted request to rename a principal.

PAC parsing in MIT Kerberos 5 (aka krb5) before 1.19.4 and 1.20.x before 1.20.1 has integer overflows that may lead to remote code execution (in KDC, kadmind, or a GSS or Kerberos application server) on 32-bit platforms (which have a resultant heap-based buffer overflow), and cause a denial of service on other platforms. This occurs in krb5_pac_parse in lib/krb5/krb/pac.c. Heimdal before 7.7.1 has "a similar bug."

kdc/do_tgs_req.c in MIT Kerberos 5 (aka krb5) 1.21 before 1.21.2 has a double free that is reachable if an authenticated user can trigger an authorization-data handling failure. Incorrect data is copied from one ticket to another.

The kadm5_modify_policy_internal function in lib/kadm5/srv/svr_policy.c in the Kerberos administration daemon (kadmind) in MIT Kerberos 5 (krb5) 1.5 through 1.6.2 does not properly check return values when the policy does not exist, which might allow remote authenticated users with the "modify policy" privilege to execute arbitrary code via unspecified vectors that trigger a write to an uninitialized pointer.

Integer signedness error in the gssrpc__svcauth_unix function in svc_auth_unix.c in the RPC library in MIT Kerberos 5 (krb5) 1.6.1 and earlier might allow remote attackers to execute arbitrary code via a negative length value.

ec_verify in kdc/kdc_preauth_ec.c in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) before 1.18.4 and 1.19.x before 1.19.2 allows remote attackers to cause a NULL pointer dereference and daemon crash. This occurs because a return value is not properly managed in a certain situation.

Double free vulnerabilities in the error handling code for ASN.1 decoders in the (1) Key Distribution Center (KDC) library and (2) client library for MIT Kerberos 5 (krb5) 1.3.4 and earlier may allow remote attackers to execute arbitrary code.

A flaw was found in, Fedora versions of krb5 from 1.16.1 to, including 1.17.x, in the way a Kerberos client could crash the KDC by sending one of the RFC 4556 "enctypes". A remote unauthenticated user could use this flaw to crash the KDC.

MIT Kerberos 5 (aka krb5) before 1.17.2 and 1.18.x before 1.18.3 allows unbounded recursion via an ASN.1-encoded Kerberos message because the lib/krb5/asn.1/asn1_encode.c support for BER indefinite lengths lacks a recursion limit.

Buffer overflow in MIT Kerberos 5 (krb5) 1.2.2 and earlier allows remote attackers to cause a denial of service and possibly execute arbitrary code via base-64 encoded data, which is not properly handled when the radix_encode function processes file glob output from the ftpglob function.

The Kerberos 4 support in KDC in MIT Kerberos 5 (krb5kdc) does not properly clear the unused portion of a buffer when generating an error message, which might allow remote attackers to obtain sensitive information, aka "Uninitialized stack values."

telnetd in GNU Inetutils through 2.3, MIT krb5-appl through 1.0.3, and derivative works has a NULL pointer dereference via 0xff 0xf7 or 0xff 0xf8. In a typical installation, the telnetd application would crash but the telnet service would remain available through inetd. However, if the telnetd application has many crashes within a short time interval, the telnet service would become unavailable after inetd logs a "telnet/tcp server failing (looping), service terminated" error. NOTE: MIT krb5-appl is not supported upstream but is shipped by a few Linux distributions. The affected code was removed from the supported MIT Kerberos 5 (aka krb5) product many years ago, at version 1.8.

In MIT Kerberos 5 (aka krb5) before 1.22.3, there is a NULL pointer dereference if an application calls gss_accept_sec_context() on a system with a NegoEx mechanism registered in /etc/gss/mech. An unauthenticated remote attacker can trigger this, causing the process to terminate in parse_nego_message.

In MIT Kerberos 5 (aka krb5) before 1.22.3, there is an integer underflow and resultant out-of-bounds read if an application calls gss_accept_sec_context() on a system with a NegoEx mechanism registered in /etc/gss/mech. An unauthenticated remote attacker can trigger this, possibly causing the process to terminate in parse_message.

In MIT Kerberos 5 (aka krb5) before 1.21.3, an attacker can modify the plaintext Extra Count field of a confidential GSS krb5 wrap token, causing the unwrapped token to appear truncated to the application.

The add_to_history function in svr_principal.c in libkadm5srv for MIT Kerberos 5 (krb5) up to 1.3.5, when performing a password change, does not properly track the password policy's history count and the maximum number of keys, which can cause an array index out-of-bounds error and may allow authenticated users to execute arbitrary code via a heap-based buffer overflow.

sudo, when linked with MIT Kerberos 5 (krb5), does not properly check whether a user can currently authenticate to Kerberos, which allows local users to gain privileges, in a manner unintended by the sudo security model, via certain KRB5_ environment variable settings. NOTE: another researcher disputes this vulnerability, stating that the attacker must be "a user, who can already log into your system, and can already use sudo."

The dtlogin program in Compaq Tru64 UNIX allows local users to gain root privileges.

lib/gssapi/krb5/iakerb.c in MIT Kerberos 5 (aka krb5) before 1.14 relies on an inappropriate context handle, which allows remote attackers to cause a denial of service (incorrect pointer read and process crash) via a crafted IAKERB packet that is mishandled during a gss_inquire_context call.

Use-after-free vulnerability in the gss_indicate_mechs function in lib/gssapi/mechglue/g_initialize.c in MIT Kerberos 5 (krb5) has unknown impact and attack vectors. NOTE: this might be the result of a typo in the source code.

Double free vulnerability in the gss_krb5int_make_seal_token_v3 function in lib/gssapi/krb5/k5sealv3.c in MIT Kerberos 5 (krb5) has unknown impact and attack vectors.

The kg_accept_krb5 function in krb5/accept_sec_context.c in the GSS-API library in MIT Kerberos 5 (aka krb5) through 1.7.1 and 1.8 before 1.8.2, as used in kadmind and other applications, does not properly check for invalid GSS-API tokens, which allows remote authenticated users to cause a denial of service (NULL pointer dereference and daemon crash) via an AP-REQ message in which the authenticator's checksum field is missing.

Use-after-free vulnerability in kadmin/server/server_stubs.c in kadmind in MIT Kerberos 5 (aka krb5) 1.5 through 1.6.3 allows remote authenticated users to cause a denial of service (daemon crash) via a request from a kadmin client that sends an invalid API version number.

Multiple memory leaks in kadmin/server/server_stubs.c in kadmind in MIT Kerberos 5 (aka krb5) before 1.13.4 and 1.14.x before 1.14.1 allow remote authenticated users to cause a denial of service (memory consumption) via a request specifying a NULL principal name.

An authentication bypass flaw was found in the way krb5's certauth interface before 1.16.1 handled the validation of client certificates. A remote attacker able to communicate with the KDC could potentially use this flaw to impersonate arbitrary principals under rare and erroneous circumstances.

lib/kadm5/kadm_rpc_xdr.c in MIT Kerberos 5 (aka krb5) before 1.20.2 and 1.21.x before 1.21.1 frees an uninitialized pointer. A remote authenticated user can trigger a kadmind crash. This occurs because _xdr_kadm5_principal_ent_rec does not validate the relationship between n_key_data and the key_data array count.

MIT krb5 1.6 or later allows an authenticated kadmin with permission to add principals to an LDAP Kerberos database to cause a denial of service (NULL pointer dereference) or bypass a DN container check by supplying tagged data that is internal to the database module.