Vulnerabilities

A flaw was found in Samba's CTDB, the clustered database service used by Samba. Insufficient integrity validation of received CTDB protocol packets allows malformed packets containing invalid field lengths, improperly terminated strings, or inconsistent packet sizes to be processed without adequate bounds checking. A remote attacker with access to the CTDB private network may trigger a denial of service through process crashes or excessive memory consumption and, in limited cases, disclose adjacent memory contents.

rsync daemon before 3.5.0 contains an IP address spoofing vulnerability that allows unauthenticated remote attackers to bypass IP-based access controls by sending a crafted PROXY protocol header with a forged source address. Attackers who can connect directly to the rsync daemon can inject a spoofed source IP in the PROXY protocol header to circumvent hosts allow/deny rules, gaining unauthorized access that would otherwise be blocked based on their real source address.

A flaw was found in Samba. A remote attacker can exploit a misconfiguration in Samba file servers and classic domain controllers that use the "check password script" feature. If this script is configured with the %u substitution character, the client-controlled username is passed without proper escaping of shell meta-characters. This vulnerability allows an attacker to achieve remote command execution on the affected system. This issue primarily affects non-standard configurations where the "check password script" is used with %u and the samba-dcerpcd service is started as a system service.

A flaw was found in Samba’s certificate auto-enrollment Group Policy handling. When certificate auto-enrollment is enabled, Samba may retrieve a CA certificate over an unencrypted HTTP connection and install it into the local trust store without proper verification. An attacker with the ability to intercept or redirect network traffic could exploit this behavior to supply a malicious certificate authority certificate, potentially allowing interception or spoofing of trusted communications.

A flaw was found in the Samba printing subsystem. Samba passes the client-controlled job description string to the command configured with the "print command" setting via the "%J" substitution character without escaping shell meta characters. A remote attacker could exploit this vulnerability by sending a specially crafted print job description that contains unescaped shell characters. This could lead to remote code execution on the affected system.

Rsync versions before 3.4.3 contain a time-of-check to time-of-use (TOCTOU) race condition in daemon file handling that allows attackers to redirect file writes outside intended directories by replacing parent directory components with symbolic links. Attackers with write access to a module path can exploit this race condition to create or overwrite arbitrary files, potentially modifying sensitive system files and achieving privilege escalation when the daemon runs with elevated privileges. This vulnerability can only be triggered if the chroot setting is false.

In rsync 3.0.1 through 3.4.1, receive_xattr relies on an untrusted length value during a qsort call, leading to a receiver use-after-free. The victim must run rsync with -X (aka --xattrs). On Linux, many (but not all) common configurations are vulnerable. Non-Linux platforms are more widely vulnerable.

A flaw was found in Samba. The smbd service daemon does not pick up group membership changes when re-authenticating an expired SMB session. This issue can expose file shares until clients disconnect and then connect again.

CVE-2024-12084 is a critical (CVSS 9.8) heap-based buffer overflow in the rsync daemon, caused by improper handling of an attacker-controlled checksum length (s2length): when MAX_DIGEST_LEN exceeds the fixed SUM_LENGTH of 16 bytes, a connecting peer can cause an out-of-bounds write into the fixed-size sum2 buffer. A remote attacker who can reach the rsync daemon needs no privileges or user interaction to trigger the flaw, and the resulting heap corruption can lead to remote code execution on the server (as demonstrated in the referenced Google security research) or crash the daemon. Any system running a vulnerable rsync daemon is affected — including rsync shipped with Red Hat Enterprise Linux, SUSE Linux, AlmaLinux, Arch Linux, Gentoo, NixOS and SmartOS — with the highest risk on servers where the daemon is exposed on TCP port 873. No confirmed in-the-wild exploitation is documented yet (the CVE is not on CISA KEV), but a public proof-of-concept exists from Google Cloud researchers and EPSS assigns a 72.1% probability of exploitation within 30 days, indicating high imminent risk.

Do: Upgrade rsync to 3.4.1 or later, or install the patched rsync package from your distribution (Red Hat, SUSE, AlmaLinux, Arch, Gentoo, NixOS and SmartOS have all shipped fixes). Until patched, restrict TCP port 873 to trusted networks or disable the rsync daemon where it is not needed. Audit hosts for listening rsync daemons and verify the installed rsync version against your vendor's advisory.

A flaw was found in rsync which could be triggered when rsync compares file checksums. This flaw allows an attacker to manipulate the checksum length (s2length) to cause a comparison between a checksum and uninitialized memory and leak one byte of uninitialized stack data at a time.

Missing Authorization vulnerability in SAMPAŞ Holding AKOS (AkosCepVatandasService), SAMPAŞ Holding AKOS (TahsilatService) allows Collect Data as Provided by Users. This issue affects AKOS (AkosCepVatandasService): before V2.0; AKOS (TahsilatService): before V1.0.7.

A design flaw was found in Samba's DirSync control implementation, which exposes passwords and secrets in Active Directory to privileged users and Read-Only Domain Controllers (RODCs). This flaw allows RODCs and users possessing the GET_CHANGES right to access all attributes, including sensitive secrets and passwords. Even in a default setup, RODC DC accounts, which should only replicate some passwords, can gain access to all domain secrets, including the vital krbtgt, effectively eliminating the RODC / DC distinction. Furthermore, the vulnerability fails to account for error conditions (fail open), like out-of-memory situations, potentially granting access to secret attributes, even under low-privileged attacker influence.

A vulnerability was found in Samba's "rpcecho" development server, a non-Windows RPC server used to test Samba's DCE/RPC stack elements. This vulnerability stems from an RPC function that can be blocked indefinitely. The issue arises because the "rpcecho" service operates with only one worker in the main RPC task, allowing calls to the "rpcecho" server to be blocked for a specified time, causing service disruptions. This disruption is triggered by a "sleep()" call in the "dcesrv_echo_TestSleep()" function under specific conditions. Authenticated users or attackers can exploit this vulnerability to make calls to the "rpcecho" server, requesting it to block for a specified duration, effectively disrupting most services and leading to a complete denial of service on the AD DC. The DoS affects all other services as "rpcecho" runs in the main RPC task.

A path traversal vulnerability was identified in Samba when processing client pipe names connecting to Unix domain sockets within a private directory. Samba typically uses this mechanism to connect SMB clients to remote procedure call (RPC) services like SAMR LSA or SPOOLSS, which Samba initiates on demand. However, due to inadequate sanitization of incoming client pipe names, allowing a client to send a pipe name containing Unix directory traversal characters (../). This could result in SMB clients connecting as root to Unix domain sockets outside the private directory. If an attacker or client managed to send a pipe name resolving to an external service using an existing Unix domain socket, it could potentially lead to unauthorized access to the service and consequential adverse events, including compromise or service crashes.

A heap-based Buffer Overflow flaw was discovered in Samba. It could allow a remote, authenticated attacker to exploit this vulnerability to cause a denial of service.

An infinite loop vulnerability was found in Samba's mdssvc RPC service for Spotlight. When parsing Spotlight mdssvc RPC packets sent by the client, the core unmarshalling function sl_unpack_loop() did not validate a field in the network packet that contains the count of elements in an array-like structure. By passing 0 as the count value, the attacked function will run in an endless loop consuming 100% CPU. This flaw allows an attacker to issue a malformed RPC request, triggering an infinite loop, resulting in a denial of service condition.

The fix in 4.6.16, 4.7.9, 4.8.4 and 4.9.7 for CVE-2018-10919 Confidential attribute disclosure vi LDAP filters was insufficient and an attacker may be able to obtain confidential BitLocker recovery keys from a Samba AD DC.