CVE-2015-5296

Samba 3.x and 4.x before 4.1.22, 4.2.x before 4.2.7, and 4.3.x before 4.3.3 supports connections that are encrypted but unsigned, which allows man-in-the-middle attackers to conduct encrypted-to-unencrypted downgrade attacks by modifying the client-server data stream, related to clidfs.c, libsmb_server.c, and smbXcli_base.c.

Updated ldb and samba packages fix security vulnerabilities:

A malicious client can send packets that cause the LDAP server in the samba daemon process to become unresponsive, preventing the server from servicing any other requests (CVE-2015-3223).

Versions of Samba from 3.0.0 to 4.3.2 inclusive are vulnerable to a bug in symlink verification, which under certain circumstances could allow client access to files outside the exported share path (CVE-2015-5252).

Versions of Samba from 3.2.0 to 4.3.2 inclusive do not ensure that signing is negotiated when creating an encrypted client connection to a server. Without this, a man-in-the-middle attack could downgrade the connection and connect using the supplied credentials as an unsigned, unencrypted connection (CVE-2015-5296).

Versions of Samba from 3.2.0 to 4.3.2 inclusive are vulnerable to a missing access control check in the vfs_shadow_copy2 module, which could allow unauthorized users to access snapshots (CVE-2015-5299).

A malicious client can send packets that cause the LDAP server in the samba daemon process to return heap memory beyond the length of the requested value. This memory may contain data that the client should not be allowed to see, allowing compromise of the server (CVE-2015-5330).

The talloc, tdb, tevent, and ldb packages have been updated to their lastest versions, and the samba package has been patched to fix these issues.

These are all security issues fixed in the ctdb-4.5.0-1.1 package on the GA media of openSUSE Tumbleweed.

This update for ldb, samba, talloc, tdb, tevent fixes the following security issues:

• ldb was updated to version 1.1.24.

  • Fix ldap \00 search expression attack dos; CVE-2015-3223; (bso#11325)
  • Fix remote read memory exploit in ldb; CVE-2015-5330; (bso#11599)
  • Move ldb_(un)pack_data into ldb_module.h for testing
  • Fix installation of _ldb_text.py
  • Fix propagation of ldb errors through tdb
  • Fix bug triggered by having an empty message in database during search

• Move the ldb-cmdline library to the ldb-tools package as the packaged binaries depend on it.

• Update the samba library distribution key file 'ldb.keyring'; (bso#945116).

Samba was updated to fix these issues:

• Malicious request can cause samba ldap server to hang, spinning using cpu; CVE-2015-3223; (bso#11325); (bsc#958581).
• Remote read memory exploit in ldb; cve-2015-5330; (bso#11599); (bsc#958586).
• Insufficient symlink verification (file access outside the share); CVE-2015-5252; (bso#11395); (bsc#958582).
• No man in the middle protection when forcing smb encryption on the client side; CVE-2015-5296; (bso#11536); (bsc#958584).
• Currently the snapshot browsing is not secure thru windows previous version (shadow_copy2); CVE-2015-5299; (bso#11529); (bsc#958583).
• Fix microsoft ms15-096 to prevent machine accounts from being changed into user accounts; CVE-2015-8467; (bso#11552); (bsc#958585).
• Changing log level of two entries to from 1 to 3; (bso#9912).
• Vfs_gpfs: re-enable share modes; (bso#11243).
• Wafsamba: also build libraries with relro protection; (bso#11346).
• Ctdb: strip trailing spaces from nodes file; (bso#11365).
• S3-smbd: fix old dos client doing wildcard delete - gives a attribute type of zero; (bso#11452).
• Nss_wins: do not run into use after free issues when we access memory allocated on the globals and the global being reinitialized; (bso#11563).
• Async_req: fix non-blocking connect(); (bso#11564).
• Auth: gensec: fix a memory leak; (bso#11565).
• Lib: util: make non-critical message a warning; (bso#11566).
• Fix winbindd crashes with samlogon for trusted domain user; (bso#11569); (bsc#949022).
• Smbd: send smb2 oplock breaks unencrypted; (bso#11570).
• Ctdb: open the ro tracking db with perms 0600 instead of 0000; (bso#11577).
• Manpage: correct small typo error; (bso#11584).
• S3: smbd: if ea's are turned off on a share don't allow an smb2 create containing them; (bso#11589).
• Backport some valgrind fixes from upstream master; (bso#11597).
• S3: smbd: have_file_open_below() fails to enumerate open files below an open directory handle; (bso#11615).
• Docs: fix some typos in the idmap config section of man 5 smb.conf; (bso#11619).
• Cleanup and enhance the pidl sub package.
• S3: smbd: fix our access-based enumeration on 'hide unreadable' to match Windows; (bso#10252).
• Smbd: fix file name buflen and padding in notify repsonse; (bso#10634).
• Kerberos: make sure we only use prompter type when available; (bso#11038).
• S3:ctdbd_conn: make sure we destroy tevent_fd before closing the socket; (bso#11316).
• Dcerpc.idl: accept invalid dcerpc_bind_nak pdus; (bso#11327).
• Fix a deadlock in tdb; (bso#11381).
• S3: smbd: fix mkdir race condition; (bso#11486).
• Pam_winbind: fix a segfault if initialization fails; (bso#11502).
• S3: dfs: fix a crash when the dfs targets are disabled; (bso#11509).
• S3: smbd: fix opening/creating :stream files on the root share directory; (bso#11522).
• Net: fix a crash with 'net ads keytab create'; (bso#11528).
• S3: smbd: fix a crash in unix_convert() and a null pointer bug introduced by previous 'raw' stream fix (bso#11522); (bso#11535).
• Vfs_fruit: return value of ad_pack in vfs_fruit.c; (bso#11543).
• Vfs_commit: set the fd on open before calling smb_vfs_fstat; (bso#11547).
• Fix bug in smbstatus where the lease info is not printed; (bso#11549).
• S3:smbstatus: add stream name to share_entry_forall(); (bso#11550).
• Prevent null pointer access in…

This update for ldb, samba, talloc, tdb, tevent fixes the following security issues and bugs:

The Samba LDB was updated to version 1.1.24:

• Fix ldap \00 search expression attack dos; CVE-2015-3223; (bso#11325)
• Fix remote read memory exploit in ldb; CVE-2015-5330; (bso#11599)
• Move ldb_(un)pack_data into ldb_module.h for testing
• Fix installation of _ldb_text.py
• Fix propagation of ldb errors through tdb
• Fix bug triggered by having an empty message in database during search

Samba was updated to fix these issues:

• Malicious request can cause Samba LDAP server to hang, spinning using CPU; CVE-2015-3223; (bso#11325); (bnc#958581).
• Remote read memory exploit in LDB; CVE-2015-5330; (bso#11599); (bnc#958586).
• Insufficient symlink verification (file access outside the share); CVE-2015-5252; (bso#11395); (bnc#958582).
• No man in the middle protection when forcing smb encryption on the client side; CVE-2015-5296; (bso#11536); (bnc#958584).
• Currently the snapshot browsing is not secure thru windows previous version (shadow_copy2); CVE-2015-5299; (bso#11529); (bnc#958583).
• Fix Microsoft MS15-096 to prevent machine accounts from being changed into user accounts; CVE-2015-8467; (bso#11552); (bnc#958585).
• Changing log level of two entries to from 1 to 3; (bso#9912).
• vfs_gpfs: Re-enable share modes; (bso#11243).
• wafsamba: Also build libraries with RELRO protection; (bso#11346).
• ctdb: Strip trailing spaces from nodes file; (bso#11365).
• s3-smbd: Fix old DOS client doing wildcard delete - gives a attribute type of zero; (bso#11452).
• nss_wins: Do not run into use after free issues when we access memory allocated on the globals and the global being reinitialized; (bso#11563).
• async_req: Fix non-blocking connect(); (bso#11564).
• auth: gensec: Fix a memory leak; (bso#11565).
• lib: util: Make non-critical message a warning; (bso#11566).
• Fix winbindd crashes with samlogon for trusted domain user; (bso#11569); (bnc#949022).
• smbd: Send SMB2 oplock breaks unencrypted; (bso#11570).
• ctdb: Open the RO tracking db with perms 0600 instead of 0000; (bso#11577).
• manpage: Correct small typo error; (bso#11584).
• s3: smbd: If EA's are turned off on a share don't allow an SMB2 create containing them; (bso#11589).
• Backport some valgrind fixes from upstream master; (bso#11597).
• s3: smbd: have_file_open_below() fails to enumerate open files below an open directory handle; (bso#11615).
• docs: Fix some typos in the idmap config section of man 5 smb.conf; (bso#11619).
• Cleanup and enhance the pidl sub package.
• s3: smbd: Fix our access-based enumeration on 'hide unreadable' to match Windows; (bso#10252).
• smbd: Fix file name buflen and padding in notify repsonse; (bso#10634).
• kerberos: Make sure we only use prompter type when available; (bso#11038).
• s3:ctdbd_conn: Make sure we destroy tevent_fd before closing the socket; (bso#11316).
• dcerpc.idl: accept invalid dcerpc_bind_nak pdus; (bso#11327).
• Fix a deadlock in tdb; (bso#11381).
• s3: smbd: Fix mkdir race condition; (bso#11486).
• pam_winbind: Fix a segfault if initialization fails; (bso#11502).
• s3: dfs: Fix a crash when the dfs targets are disabled; (bso#11509).
• s3: smbd: Fix opening/creating :stream files on the root share directory; (bso#11522).
• net: Fix a crash with 'net ads keytab create'; (bso#11528).
• s3: smbd: Fix a crash in unix_convert() and a NULL pointer bug introduced by previous 'raw' stream fix (bso#11522); (bso#11535).
• vfs_fruit: Return value of ad_pack in vfs_fruit.c; (bso#11543).
• vfs_commit: Set the fd on open before calling SMB_VFS_FSTAT; (bso#11547).
• Fix bug in smbstatus where the lease info is not printed; (bso#11549).
• s3:smbstatus: Add stream name to share_entry_forall(); (bso#11550).
• Prevent null pointer access in samlogon fallback when security credentials are null; (bnc#949022).
• Fix 100% CPU in winbindd when logging in with 'user must change password on next logon'; (bso#11038). …

This update for Samba fixes the following security issues:

• CVE-2015-5330: Remote read memory exploit in LDB (bnc#958586).
• CVE-2015-5252: Insufficient symlink verification (file access outside the share) (bnc#958582).
• CVE-2015-5296: No man in the middle protection when forcing smb encryption on the client side (bnc#958584).
• CVE-2015-5299: Currently the snapshot browsing is not secure thru windows previous version (shadow_copy2) (bnc#958583).

Non-security issues fixed:

• Prevent null pointer access in samlogon fallback when security credentials are null (bnc#949022).
• Address unrecoverable winbind failure: 'key length too large' (bnc#934299).
• Take resource group sids into account when caching netsamlogon data (bnc#912457).
• Use domain name if search by domain SID fails to send SIDHistory lookups to correct idmap backend (bnc#773464).
• Remove deprecated base_rid example from idmap_rid manpage (bnc#913304).
• Purge printer name cache on spoolss SetPrinter change (bnc#901813).
• Fix lookup of groups with 'Local Domain' scope from Active Directory (bnc#948244).

This update for Samba fixes the following security issues:

• CVE-2015-5330: Remote read memory exploit in LDB (bnc#958586)
• CVE-2015-5252: Insufficient symlink verification (file access outside the share) (bnc#958582)
• CVE-2015-5296: No man in the middle protection when forcing smb encryption on the client side (bnc#958584)
• CVE-2015-5299: Currently the snapshot browsing is not secure thru windows previous version (shadow_copy2) (bnc#958583)

Non-security issues fixed:

• Prevent null pointer access in samlogon fallback when security credentials are null (bnc#949022)
• Ensure samlogon fall-back requests are rerouted after kerberos failure (bnc#953382)
• Ensure 'Your account is disabled' message is displayed when attempting to ssh into locked account (bnc#953382)
• Address unrecoverable winbind failure: 'key length too large' (bnc#934299)
• Take resource group sids into account when caching netsamlogon data (bnc#912457)
• Fix lookup of groups with 'Local Domain' scope from Active Directory (bnc#948244)
• dependency issue with samba-winbind (bnc#936909)

Thilo Uttendorfer discovered that the Samba LDAP server incorrectly handled certain packets. A remote attacker could use this issue to cause the LDAP server to stop responding, resulting in a denial of service. This issue only affected Ubuntu 14.04 LTS, Ubuntu 15.04 and Ubuntu 15.10. (CVE-2015-3223)

Jan Kasprzak discovered that Samba incorrectly handled certain symlinks. A remote attacker could use this issue to access files outside the exported share path. (CVE-2015-5252)

Stefan Metzmacher discovered that Samba did not enforce signing when creating encrypted connections. If a remote attacker were able to perform a machine-in-the-middle attack, this flaw could be exploited to view sensitive information. (CVE-2015-5296)

It was discovered that Samba incorrectly performed access control when using the VFS shadow_copy2 module. A remote attacker could use this issue to access snapshots, contrary to intended permissions. (CVE-2015-5299)

Douglas Bagnall discovered that Samba incorrectly handled certain string lengths. A remote attacker could use this issue to possibly access sensitive information. (CVE-2015-5330)

It was discovered that the Samba LDAP server incorrectly handled certain packets. A remote attacker could use this issue to cause the LDAP server to stop responding, resulting in a denial of service. This issue only affected Ubuntu 14.04 LTS, Ubuntu 15.04 and Ubuntu 15.10. (CVE-2015-7540)

Andrew Bartlett discovered that Samba incorrectly checked administrative privileges during creation of machine accounts. A remote attacker could possibly use this issue to bypass intended access restrictions in certain environments. This issue only affected Ubuntu 14.04 LTS, Ubuntu 15.04 and Ubuntu 15.10. (CVE-2015-8467)