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 "dcesrvechoTestSleep()" 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 vulnerability was found in subscription-manager that allows local privilege escalation due to inadequate authorization. The D-Bus interface com.redhat.RHSM1 exposes a significant number of methods to all users that could change the state of the registration. By using the com.redhat.RHSM1.Config.SetAll() method, a low-privileged local user could tamper with the state of the registration, by unregistering the system or by changing the current entitlements. This flaw allows an attacker to set arbitrary configuration directives for /etc/rhsm/rhsm.conf, which can be abused to cause a local privilege escalation to an unconfined root.
Impact
A security issue was found in the Keylime registrar code which allows an attacker to effectively bypass the challenge-response protocol used to verify that an agent has indeed access to an AIK which in indeed related to the EK.
When an agent starts up, it will contact a registrar and provide a public EK and public AIK, in addition to the EK Certificate. This registrar will then challenge the agent to decrypt a challenge encrypted with the EK.
When receiving the wrong "authtag" back from the agent during activation, the registrar answers with an error message that contains the expected correct "authtag" (an HMAC which is calculated within the registrar for checking). An attacker could simply record the correct expected "authtag" from the HTTP error message and perform the activate call again with the correct expected "authtag" for the agent.
The security issue allows an attacker to pass the challenge-response protocol during registration with (almost) arbitrary registration data. In particular, the attacker can provide a valid EK Certificate and EK, which passes verification by the tenant (or registrar), while using a compromised AIK, which is stored unprotected outside the TPM and is unrelated to former two. The attacker then deliberately fails the initial activation call to get to know the correct "authtag" and then provides it in a subsequent activation call. This results in an agent which is (incorrectly) registered with a valid EK Certificate, but with a compromised/unrelated AIK.
Patches Users should upgrade to release 7.5.0
Impact Keylime registrar is prone to a simple denial of service attack in which an adversary opens a connection to the TLS port (by default, port 8891) blocking further, legitimate connections. As long as the connection is open, the registrar is blocked and cannot serve any further clients (agents and tenants), which prevents normal operation. The problem does not affect the verifier.
Patches Users should upgrade to release 7.4.0
CVE-2023-0494/ZDI-CAN-19596: X.Org Server DeepCopyPointerClasses use-after-free
A dangling pointer in DeepCopyPointerClasses can be exploited by ProcXkbSetDeviceInfo() and ProcXkbGetDeviceInfo() to read/write into freed memory.
A flaw was found in Keycloak in the execute-actions-email endpoint. This issue allows arbitrary HTML to be injected into emails sent to Keycloak users and can be misused to perform phishing or other attacks against users.
The Samba vfsfruit module uses extended file attributes (EA, xattr) to provide "...enhanced compatibility with Apple SMB clients and interoperability with a Netatalk 3 AFP fileserver." Samba versions prior to 4.13.17, 4.14.12 and 4.15.5 with vfsfruit configured allow out-of-bounds heap read and write via specially crafted extended file attributes. A remote attacker with write access to extended file attributes can execute arbitrary code with the privileges of smbd, typically root.
An improper link resolution flaw while extracting an archive can lead to changing the access control list (ACL) of the target of the link. An attacker may provide a malicious archive to a victim user, who would trigger this flaw when trying to extract the archive. A local attacker may use this flaw to change the ACL of a file on the system and gain more privileges.
An improper link resolution flaw can occur while extracting an archive leading to changing modes, times, access control lists, and flags of a file outside of the archive. An attacker may provide a malicious archive to a victim user, who would trigger this flaw when trying to extract the archive. A local attacker may use this flaw to gain more privileges in a system.
A flaw was found in the way Samba, as an Active Directory Domain Controller, implemented Kerberos name-based authentication. The Samba AD DC, could become confused about the user a ticket represents if it did not strictly require a Kerberos PAC and always use the SIDs found within. The result could include total domain compromise.
A flaw was found in the way Samba maps domain users to local users. An authenticated attacker could use this flaw to cause possible privilege escalation.
A flaw was found in the way samba implemented SMB1 authentication. An attacker could use this flaw to retrieve the plaintext password sent over the wire even if Kerberos authentication was required.
A flaw was found in the Linux kernel. A memory leak in the ccp-ops crypto driver can allow attackers to cause a denial of service. This vulnerability is similar with the older CVE-2019-18808. The highest threat from this vulnerability is to system availability.
A flaw was found in c-ares library, where a missing input validation check of host names returned by DNS (Domain Name Servers) can lead to output of wrong hostnames which might potentially lead to Domain Hijacking. The highest threat from this vulnerability is to confidentiality and integrity as well as system availability.
A flaw was found in the KVM's AMD code for supporting SVM nested virtualization. The flaw occurs when processing the VMCB (virtual machine control block) provided by the L1 guest to spawn/handle a nested guest (L2). Due to improper validation of the "virtext" field, this issue could allow a malicious L1 to disable both VMLOAD/VMSAVE intercepts and VLS (Virtual VMLOAD/VMSAVE) for the L2 guest. As a result, the L2 guest would be allowed to read/write physical pages of the host, resulting in a crash of the entire system, leak of sensitive data or potential guest-to-host escape.
A flaw was found in pki-core 10.10. Older versions are not affected.
When the pkispawn command is run in debug mode, admin credentials are stored in the installation log file, which is world readable.
A NULL pointer dereference flaw was found in the Linux kernel’s IEEE 802.15.4 wireless networking subsystem in the way the user closes the LR-WPAN connection. This flaw allows a local user to crash the system. The highest threat from this vulnerability is to system availability.
An information disclosure vulnerability was found in libvirt in versions before 6.3.0. HTTP cookies used to access network-based disks were saved in the XML dump of the guest domain. This flaw allows an attacker to access potentially sensitive information in the domain configuration via the dumpxml command.
An improper authorization flaw was discovered in systemd-resolved in the way it configures the exposed DBus interface org.freedesktop.resolve1. An unprivileged local attacker could call all DBus methods, even when marked as privileged operations. An attacker could abuse this flaw by changing the DNS, Search Domain, LLMNR, DNSSEC and other network link settings without any authorization, allowing control of the network names resolution process and cause the system to communicate with wrong or malicious servers.
An issue was discovered in sd-bus in systemd 239. busprocessobject() in libsystemd/sd-bus/bus-objects.c allocates a variable-length stack buffer for temporarily storing the object path of incoming D-Bus messages. An unprivileged local user can exploit this by sending a specially crafted message to PID1, causing the stack pointer to jump over the stack guard pages into an unmapped memory region and trigger a denial of service (systemd PID1 crash and kernel panic).
A flaw was found in systemd-journald. An out-of-bounds read when parsing a crafted syslog message that could lead to information disclosure.
A use-after-free vulnerability was found in a network namespaces code affecting the Linux kernel since v4.0-rc1 through v4.15-rc5. The function getnetnsbyid() does not check for the net::count value after it has found a peer network in netnsids idr which could lead to double free and memory corruption. This vulnerability could allow an unprivileged local user to induce kernel memory corruption on the system, leading to a crash. Due to the nature of the flaw, privilege escalation cannot be fully ruled out, although we believe it is unlikely.
References:
https://marc.info/?l=linux-netdev&m=151370451121029&w=2
https://marc.info/?t=151370468900001&r=1&w=2 (a whole thread)
http://seclists.org/oss-sec/2018/q1/7
An upstream patch:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=21b5944350052d2583e82dd59b19a9ba94a007f0
Multiple unspecified vulnerabilities in the browser engine in Mozilla Firefox before 47.0 and Firefox ESR 45.x before 45.2 allow remote attackers to cause a denial of service (memory corruption and application crash) or possibly execute arbitrary code via unknown vectors.
An issue was discovered in the linux kernel's tty subsystem handling during shutdown. The flaw was possible to take a reference to the ldisc during shutdown phase.
This race occurs on hangup of tty. It races and hangs on ldsemdownwrite on a semaphore that is being aquired by a new reader(CPU 1). The new reader/writer is sleeping in ldsemdownread() and the hangup is sleeping in ldsemdownwrite().
Resources:
Fix: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=cf872776fc84128bb779ce2b83a37c884c3203ae CVE request: http://seclists.org/oss-sec/2015/q2/545