Kerberos 5 (aka krb5) 1.21.2 contains a memory leak in /krb5/src/lib/rpc/pmaprmt.c.
References:
https://github.com/LuMingYinDetect/krb5defects/blob/main/krb5detect1.md
lib/kadm5/kadmrpcxdr.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 xdrkadm5principalentrec does not validate the relationship between nkeydata and the keydata array count.
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.
A Reachable Assertion issue was discovered in the KDC in MIT Kerberos 5 (aka krb5) before 1.17. If an attacker can obtain a krbtgt ticket using an older encryption type (single-DES, triple-DES, or RC4), the attacker can crash the KDC by making an S4U2Self request.
Double free vulnerability in MIT Kerberos 5 (aka krb5) allows attackers to have unspecified impact via vectors involving automatic deletion of security contexts on error.
The validateasrequest function in kdcutil.c in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) before 1.13.6 and 1.4.x before 1.14.3, when restrictanonymoustotgt is enabled, uses an incorrect client data structure, which allows remote authenticated users to cause a denial of service (NULL pointer dereference and daemon crash) via an S4U2Self request.
The processdbargs function in plugins/kdb/ldap/libkdbldap/ldapprincipal2.c in the LDAP KDB module in kadmind in MIT Kerberos 5 (aka krb5) through 1.13.4 and 1.14.x through 1.14.1 mishandles the DB argument, which allows remote authenticated users to cause a denial of service (NULL pointer dereference and daemon crash) via a crafted request to modify a principal.
Multiple memory leaks in kadmin/server/serverstubs.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.
The xdrnullstring function in lib/kadm5/kadmrpcxdr.c in kadmind in MIT Kerberos 5 (aka krb5) before 1.13.4 and 1.14.x before 1.14.1 does not verify whether '\0' characters exist as expected, which allows remote authenticated users to obtain sensitive information or cause a denial of service (out-of-bounds read) via a crafted string.
The (1) kadm5createprincipal3 and (2) kadm5modifyprincipal functions in lib/kadm5/srv/svrprincipal.c in kadmind in MIT Kerberos 5 (aka krb5) 1.12.x and 1.13.x before 1.13.4 and 1.14.x before 1.14.1 allow remote authenticated users to cause a denial of service (NULL pointer dereference and daemon crash) by specifying KADM5POLICY with a NULL policy name.
The iakerbgssexportseccontext function in lib/gssapi/krb5/iakerb.c in MIT Kerberos 5 (aka krb5) 1.14 pre-release 2015-09-14 improperly accesses a certain pointer, which allows remote authenticated users to cause a denial of service (memory corruption) or possibly have unspecified other impact by interacting with an application that calls the gssexportseccontext function. NOTE: this vulnerability exists because of an incorrect fix for CVE-2015-2696.
The buildprincipalva function in lib/krb5/krb/bldprinc.c in MIT Kerberos 5 (aka krb5) before 1.14 allows remote authenticated users to cause a denial of service (out-of-bounds read and KDC crash) via an initial '\0' character in a long realm field within a TGS request.
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 gssinquirecontext call.
lib/gssapi/spnego/spnegomech.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 SPNEGO packet that is mishandled during a gssinquirecontext call.
The kdcpreauth modules in MIT Kerberos 5 (aka krb5) 1.12.x and 1.13.x before 1.13.2 do not properly track whether a client's request has been validated, which allows remote attackers to bypass an intended preauthentication requirement by providing (1) zero bytes of data or (2) an arbitrary realm name, related to plugins/preauth/otp/main.c and plugins/preauth/pkinit/pkinitsrv.c.
MIT Kerberos 5 (aka krb5) through 1.13.1 incorrectly expects that a krb5readmessage data field is represented as a string ending with a '\0' character, which allows remote attackers to (1) cause a denial of service (NULL pointer dereference) via a zero-byte version string or (2) cause a denial of service (out-of-bounds read) by omitting the '\0' character, related to appl/useruser/server.c and lib/krb5/krb/recvauth.c.
The krb5gssprocesscontexttoken function in lib/gssapi/krb5/processcontexttoken.c in the libgssapikrb5 library in MIT Kerberos 5 (aka krb5) through 1.11.5, 1.12.x through 1.12.2, and 1.13.x before 1.13.1 does not properly maintain security-context handles, which allows remote authenticated users to cause a denial of service (use-after-free and double free, and daemon crash) or possibly execute arbitrary code via crafted GSSAPI traffic, as demonstrated by traffic to kadmind.
plugins/kdb/ldap/libkdbldap/ldapprincipal2.c in MIT Kerberos 5 (aka krb5) 1.12.x and 1.13.x before 1.13.1, when the KDC uses LDAP, allows remote authenticated users to cause a denial of service (NULL pointer dereference and daemon crash) by creating a database entry for a keyless principal, as demonstrated by a kadmin "addprincipal -nokey" or "purgekeys -all" command.
The krb5ldapgetpasswordpolicyfromdn function in plugins/kdb/ldap/libkdbldap/ldappwdpolicy.c in MIT Kerberos 5 (aka krb5) before 1.13.1, when the KDC uses LDAP, allows remote authenticated users to cause a denial of service (daemon crash) via a successful LDAP query with no results, as demonstrated by using an incorrect object type for a password policy.
It was reported that if a privileged user randomized the keys for a service principal, the old key would be returned to them. This could lead to ticket forgery attacks on the service in question.
This issue has been fixed in upstream version 1.13. Red Hat Enterprise Linux 6 and 7 are affected.
Full details from the upstream report:
"" An authenticated remote attacker can retrieve the current keys for a service principal when generating a new set of keys for that principal. The attacker needs to be authenticated as a user who has the elevated privilege for randomizing the keys of other principals.
Normally, when a Kerberos administrator randomizes the keys of a service principal, kadmind returns only the new keys. This prevents an administrator who lacks legitimate privileged access to a service from forging tickets to authenticate to that service. If the "keepold" flag to the kadmin randkey RPC operation is true, kadmind retains the old keys in the KDC database as intended, but also unexpectedly returns the old keys to the client, which exposes the service to ticket forgery attacks from the administrator.
A mitigating factor is that legitimate clients of the affected service will start failing to authenticate to the service once they begin to receive service tickets encrypted in the new keys. The affected service will be unable to decrypt the newly issued tickets, possibly alerting the legitimate administrator of the affected service. ""
Upstream patch:
https://github.com/krb5/krb5/commit/af0ed4df4dfae762ab5fb605f5a0c8f59cb4f6ca
References:
http://krbdev.mit.edu/rt/Ticket/Display.html?id=8018
It was reported [1] that, within the kadmin protocol, the access controls for getstrings/setstring were insufficient; anyone with global list privileges could get or modify string attributed on any principal.
It was also noted that the exposure depends on how generous the kadmind acl was with list permissions and whether or not string attributes were used in deployment (and noting that nothing in the core code uses them yet).
This has been fixed upstream [2] and in Fedora [3].
[1] http://krbdev.mit.edu/rt/Ticket/Display.html?user=guest&pass=guest&id=7093 [2] http://src.mit.edu/fisheye/changelog/krb5/?cs=25704 [3] http://koji.fedoraproject.org/koji/buildinfo?buildID=300840
It was reported [1] that, within the kadmin protocol, the access controls for getstrings/setstring were insufficient; anyone with global list privileges could get or modify string attributed on any principal.
It was also noted that the exposure depends on how generous the kadmind acl was with list permissions and whether or not string attributes were used in deployment (and noting that nothing in the core code uses them yet).
This has been fixed upstream [2] and in Fedora [3].
[1] http://krbdev.mit.edu/rt/Ticket/Display.html?user=guest&pass=guest&id=7093 [2] http://src.mit.edu/fisheye/changelog/krb5/?cs=25704 [3] http://koji.fedoraproject.org/koji/buildinfo?buildID=300840
The krb5ldaplockoutaudit function in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) 1.8 through 1.8.4 and 1.9 through 1.9.1, when the LDAP back end is used, allows remote attackers to cause a denial of service (assertion failure and daemon exit) via unspecified vectors, related to the lockedcheckp function. NOTE: the Berkeley DB vector is covered by CVE-2011-4151.
The kdbldap plugin in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) 1.9 through 1.9.1, when the LDAP back end is used, allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via a kinit operation with incorrect string case for the realm, related to the isprincipalinrealm, krb5seterrormessage, krb5ldapgetprincipal, and processasreq functions.
The lookuplockoutpolicy function in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) 1.8 through 1.8.4 and 1.9 through 1.9.1, when the db2 (aka Berkeley DB) or LDAP back end is used, allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via vectors that trigger certain processasreq errors.
The krb5db2lockoutaudit function in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) 1.8 through 1.8.4, when the db2 (aka Berkeley DB) back end is used, allows remote attackers to cause a denial of service (assertion failure and daemon exit) via unspecified vectors, a different vulnerability than CVE-2011-1528.
It was found that the kerberized FTP server did not properly check for the failure to set its effective group identifier (GID). A remote, authenticated FTP user could use this flaw to gain unauthorized read or write access to files whose group owner was the initial effective GID of the FTP daemon process.
References: [1] http://web.mit.edu/kerberos/advisories/MITKRB5-SA-2011-005.txt (not public yet) [2] http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2011-1526
Upstream patch: [3] http://web.mit.edu/kerberos/advisories/2011-005-patch.txt
Acknowledgements:
Red Hat would like to thank the MIT Kerberos project for reporting this issue. Upstream acknowledges Tim Zingelman as the original reporter.
The processchpwrequest function in schpw.c in the password-changing functionality in kadmind in MIT Kerberos 5 (aka krb5) 1.7 through 1.9 frees an invalid pointer, which allows remote attackers to execute arbitrary code or cause a denial of service (daemon crash) via a crafted request that triggers an error condition.
Double free vulnerability in the prepareerroras function in doasreq.c in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) 1.7 through 1.9, when the PKINIT feature is enabled, allows remote attackers to cause a denial of service (daemon crash) or possibly execute arbitrary code via an edata field containing typed data.
The Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) 1.9 allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via a malformed request packet that does not trigger a response packet.