Freebsd : Security Vulnerabilities, CVEs, (Gain Privilege) CVSS score >= 4

pam_krb5 authenticates a user by essentially running kinit with the password, getting a ticket-granting ticket (tgt) from the Kerberos KDC (Key Distribution Center) over the network, as a way to verify the password. However, if a keytab is not provisioned on the system, pam_krb5 has no way to validate the response from the KDC, and essentially trusts the tgt provided over the network as being valid. In a non-default FreeBSD installation that leverages pam_krb5 for authentication and does not have a keytab provisioned, an attacker that is able to control both the password and the KDC responses can return a valid tgt, allowing authentication to occur for any user on the system.

The implementations of EAP-PWD in wpa_supplicant EAP Peer, when built against a crypto library missing explicit validation on imported elements, do not validate the scalar and element values in EAP-pwd-Commit. An attacker may complete authentication, session key and control of the data connection with a client. Both hostapd with SAE support and wpa_supplicant with SAE support prior to and including version 2.4 are affected. Both hostapd with EAP-pwd support and wpa_supplicant with EAP-pwd support prior to and including version 2.7 are affected.

The implementations of EAP-PWD in hostapd EAP Server, when built against a crypto library missing explicit validation on imported elements, do not validate the scalar and element values in EAP-pwd-Commit. An attacker may be able to use invalid scalar/element values to complete authentication, gaining session key and network access without needing or learning the password. Both hostapd with SAE support and wpa_supplicant with SAE support prior to and including version 2.4 are affected. Both hostapd with EAP-pwd support and wpa_supplicant with EAP-pwd support prior to and including version 2.7 are affected.

A statement in the System Programming Guide of the Intel 64 and IA-32 Architectures Software Developer's Manual (SDM) was mishandled in the development of some or all operating-system kernels, resulting in unexpected behavior for #DB exceptions that are deferred by MOV SS or POP SS, as demonstrated by (for example) privilege escalation in Windows, macOS, some Xen configurations, or FreeBSD, or a Linux kernel crash. The MOV to SS and POP SS instructions inhibit interrupts (including NMIs), data breakpoints, and single step trap exceptions until the instruction boundary following the next instruction (SDM Vol. 3A; section 6.8.3). (The inhibited data breakpoints are those on memory accessed by the MOV to SS or POP to SS instruction itself.) Note that debug exceptions are not inhibited by the interrupt enable (EFLAGS.IF) system flag (SDM Vol. 3A; section 2.3). If the instruction following the MOV to SS or POP to SS instruction is an instruction like SYSCALL, SYSENTER, INT 3, etc. that transfers control to the operating system at CPL < 3, the debug exception is delivered after the transfer to CPL < 3 is complete. OS kernels may not expect this order of events and may therefore experience unexpected behavior when it occurs.

In FreeBSD 10.x before 10.4-STABLE, 10.4-RELEASE-p3, and 10.3-RELEASE-p24 named paths are globally scoped, meaning a process located in one jail can read and modify the content of POSIX shared memory objects created by a process in another jail or the host system. As a result, a malicious user that has access to a jailed system is able to abuse shared memory by injecting malicious content in the shared memory region. This memory region might be executed by applications trusting the shared memory, like Squid. This issue could lead to a Denial of Service or local privilege escalation.

The telnetd service in FreeBSD 9.3, 10.1, 10.2, 10.3, and 11.0 allows remote attackers to inject arguments to login and bypass authentication via vectors involving a "sequence of memory allocation failures."

OpenPAM Nummularia 9.2 through 10.0 does not properly handle the error reported when an include directive refers to a policy that does not exist, which causes the loaded policy chain to no be discarded and allows context-dependent attackers to bypass authentication via a login (1) without a password or (2) with an incorrect password.