Element OS versions prior to 1.8P1 and 12.2 are susceptible to a vulnerability that could allow an unauthenticated remote attacker to perform arbitrary code execution.

An issue was discovered in the Linux kernel through 5.10.1, as used with Xen through 4.14.x. The Linux kernel PV block backend expects the kernel thread handler to reset ring->xenblkd to NULL when stopped. However, the handler may not have time to run if the frontend quickly toggles between the states connect and disconnect. As a consequence, the block backend may re-use a pointer after it was freed. A misbehaving guest can trigger a dom0 crash by continuously connecting / disconnecting a block frontend. Privilege escalation and information leaks cannot be ruled out. This only affects systems with a Linux blkback.

A Null Pointer Dereference vulnerability exists in the Binary File Descriptor (BFD) library (aka libbfd), as distributed in GNU Binutils 2.34, in bfdelfgetsymbolversionstring, as demonstrated in nm-new, that can cause a denial of service via a crafted file.

External References:

https://sourceware.org/bugzilla/showbug.cgi?id=25842 https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=8d55d10ac0d112c586eaceb92e75bd9b80aadcc4

An issue was discovered in mm/mmap.c in the Linux kernel before 5.7.11. There is a race condition between certain expand functions (expanddownwards and expandupwards) and page-table free operations from an munmap call, aka CID-246c320a8cfe.

A flaw was found in the implementation of Intel Advanced Vector Extensions (AVX) where a local authenticated attacker with the ability to execute AVX instructions is able to gather AVX register state from previous AVX executions.

This could allow information disclosure of AVX register state.

A flaw was found in the Linux kernel in versions before 5.9-rc7. Traffic between two Geneve endpoints may be unencrypted when IPsec is configured to encrypt traffic for the specific UDP port used by the GENEVE tunnel allowing anyone between the two endpoints to read the traffic unencrypted. The main threat from this vulnerability is to data confidentiality.

NTP is vulnerable to a denial of service, caused by an issue when relying on unauthenticated IPv4 time sources in ntpd. By predicting transmit timestamps for use in spoofed packets, a remote attacker could exploit this vulnerability to cause the daemon to crash or system time change.

In the Linux kernel before 5.0.3, a memory leak exits in hsrdevfinalize() in net/hsr/hsrdevice.c if hsraddport fails to add a port, which may cause denial of service, aka CID-6caabe7f197d.

GNU binutils gold gold v1.11-v1.16 (GNU binutils v2.21-v2.31.1) is affected by: Improper Input Validation, Signed/Unsigned Comparison, Out-of-bounds Read. The impact is: Denial of service. The component is: gold/fileread.cc:497, elfcpp/elfcppfile.h:644. The attack vector is: An ELF file with an invalid eshoff header field must be opened.

An issue was discovered in getvdevportnodeinfo in arch/sparc/kernel/mdesc.c in the Linux kernel through 5.1.6. There is an unchecked kstrdupconst of nodeinfo->vdevport.name, which might allow an attacker to cause a denial of service (NULL pointer dereference and system crash).

A vulnerability was found in NTP. A security issue which enables an off-path attacker to prevent ntpd from synchronizing with NTP servers not using authentication. A server mode packet with spoofed source address sent to the client ntpd causes the next transmission to be rescheduled, even if the packet doesn't have a valid origin timestamp. If the packet is sent to the client frequently enough, it will stop polling the server and not be able to synchronize with it.

A flaw was reported in kernel TCP subsystem while calculating a packet round trip time, when a sysctl parameter (/proc/sys/net/ipv4/tcpminrttwlen) when is set wrongly. This causes an integer over flaw which can lead to a Denial Of Service (DOS) attack.

Additional Information: ----------------------- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=19fad20d15a6494f47f85d869f00b11343ee5c78

An issue was discovered in aiopoll() in fs/aio.c in the Linux kernel through 5.0.4. A file may be released by aiopollwake() if an expected event is triggered immediately (e.g., by the close of a pair of pipes) after the return of vfspoll(), and this will cause a use-after-free.

An issue was discovered in the Binary File Descriptor (BFD) library (aka libbfd), as distributed in GNU Binutils 2.32. It is an attempted excessive memory allocation in setupgroup in elf.c.

A malformed query response received by a recursive server in response to a query of RTYPE ANY could trigger an assertion failure while named is attempting to add the RRs in the query response to the cache. While the combination of properties which triggers the assertion should not occur in normal traffic, it is potentially possible for the assertion to be triggered deliberately by an attacker sending a specially-constructed answer having the required properties, after having engineered a scenario whereby an ANY query is sent to the recursive server for the target QNAME. A recursive server will itself only send a query of type ANY if it receives a client query of type ANY for a QNAME for which it has no RRsets at all in cache, otherwise it will respond to the client with the the RRsets that it has available.

This vulnerability occurs during the processing of an answer packet received in response to a query. As a result, recursive servers are at the greatest risk; authoritative servers are at risk only to the extent that they perform a limited set of queries.

This description is borrowed from the upstream advisory.

A defect in BIND's handling of responses containing a DNAME answer can cause a resolver to exit after encountering an assertion failure in db.c or resolver.c

During processing of a recursive response that contains a DNAME record in the answer section, BIND can stop execution after encountering an assertion error in resolver.c (error message: "INSIST((valoptions & 0x0002U) != 0) failed") or db.c (error message: "REQUIRE(targetp != ((void )0) && targetp == ((void )0)) failed").

A server encountering either of these error conditions will stop, resulting in denial of service to clients. The risk to authoritative servers is minimal; recursive servers are chiefly at risk.