A buffer overflow flaw was found in the way Linux kernel's vhost functionality that translates virtqueue buffers to IOVs logged the buffer descriptors during migration. A privileged guest user able to pass descriptors with invalid length to the host when migration is underway, could use this flaw to increase their privileges on the host.

A flaw was found in Intel graphics hardware (GPU) where a local attacker with the ability to issue commands to the GPU which could inadvertently lead to memory corruption and possibly privilege escalation.

The attacker could use the GPU blitter to perform privilege MMIO operations not limited to the address space required to function correctly. This would expose the blitter to access kernel memory with a specially crafted request to the blitter.

Affected hardware:

- Ivy Bridge(Gen 7) and later, - Cherry Trail (Gen8) and newer mobile, desktop and embedded processors. - Intel Xeon E3-1200 v4 and later product families.

Withdrawn Advisory This advisory has been withdrawn because the vulnerability only affects the Qpid Proton C library and not org.apache.qpid:proton-j. This link has been maintained to preserve external references.

Original Description

While investigating bug PROTON-2014, we discovered that under some circumstances Apache Qpid Proton versions 0.9 to 0.27.0 (C library and its language bindings) can connect to a peer anonymously using TLS even when configured to verify the peer certificate while used with OpenSSL versions before 1.1.0. This means that an undetected man in the middle attack could be constructed if an attacker can arrange to intercept TLS traffic.

A flaw named FragmentSmack was found in the way the Linux kernel handled reassembly of fragmented IPv4 and IPv6 packets. A remote attacker could use this flaw to trigger time and calculation expensive fragment reassembly algorithms by sending specially crafted packets which could lead to a CPU saturation and hence a denial of service on the system.

External References:

https://access.redhat.com/articles/3553061

https://www.kb.cert.org/vuls/id/641765

A fix is a merge commit in the Linux kernel tree:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c30f1fc041b74ecdb072dd44f858750414b8b19f

consisting of the following commits:

7969e5c40dfd04799d4341f1b7cd266b6e47f227 385114dec8a49b5e5945e77ba7de6356106713f4 fa0f527358bd900ef92f925878ed6bfbd51305cc

A flaw named SegmentSmack was found in the way the Linux kernel handled specially crafted TCP packets. A remote attacker could use this flaw to trigger time and calculation expensive calls to tcpcollapseofoqueue() and tcppruneofoqueue() functions by sending specially modified packets within ongoing TCP sessions which could lead to a CPU saturation and hence a denial of service on the system. Maintaining the denial of service condition requires continuous two-way TCP sessions to a reachable open port, thus the attacks cannot be performed using spoofed IP addresses.

A vulnerability was found in the fs/inode.c:inodeinitowner() function logic of the LInux kernel that allows local users to create files with an unintended group ownership and with group execution and SGID permission bits set, in a scenario where a directory is SGID and belongs to a certain group and is writable by a user who is not a member of this group. This can lead to excessive permissions granted in case when they should not.

An address corruption flaw was discovered in the Linux kernel built with hardware breakpoint (CONFIGHAVEHWBREAKPOINT) support. While modifying a h/w breakpoint via 'modifyuserhwbreakpoint' routine, an unprivileged user/process could use this flaw to crash the system kernel resulting in DoS OR to potentially escalate privileges on a the system.

A flaw was found in the way the Linux kernel's KVM hypervisor handled exceptions delivered after a stack switch operation via Mov SS or Pop SS instructions. During the stack switch operation, processor does not deliver interrupts and exceptions, they are delivered once the first instruction after the stack switch is executed.

An unprivileged KVM guest user could use this flaw to crash the guest and/or potentially escalate their privileges in the guest.

Upstream patch: --------------- -> https://git.kernel.org/linus/32d43cd391bacb5f0814c2624399a5dad3501d09

Reference: ---------- -> http://www.openwall.com/lists/oss-security/2018/05/08/5

GNU patch does not properly sanitize patch files allowing for malicious patches to pass arbitrary shell commands to ed. An attacker could exploit this by tricking a user into applying malicious patches with the patch command.

A flaw was found in kernel versions before 4.14.8. The timercreate syscall implementation in kernel/time/posix-timers.c in the Linux kernel before 4.14.8 doesn't properly validate the sigevent->sigevnotify field, which leads to out-of-bounds access in the showtimer function (called when /proc/$PID/timers is read). This allows userspace applications to read arbitrary kernel memory (on a kernel built with CONFIGPOSIXTIMERS and CONFIGCHECKPOINTRESTORE).

References:

http://seclists.org/oss-sec/2018/q3/76

An upstream patch:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=cef31d9af908243421258f1df35a4a644604efbe

APR. Multiple issues in Perl were addressed with improved memory handling.

apache. Multiple issues were addressed by updating to version 2.4.27.

Apache Tomcat 7.x through 7.0.70 and 8.x through 8.5.4, when the CGI Servlet is enabled, follows RFC 3875 section 4.1.18 and therefore does not protect applications from the presence of untrusted client data in the HTTPPROXY environment variable, which might allow remote attackers to redirect an application's outbound HTTP traffic to an arbitrary proxy server via a crafted Proxy header in an HTTP request, aka an "httpoxy" issue. NOTE: the vendor states "A mitigation is planned for future releases of Tomcat, tracked as CVE-2016-5388"; in other words, this is not a CVE ID for a vulnerability.

apache. Multiple issues existed in Apache. These were addressed by updating Apache to version 2.4.25.

A vulnerability was found in the libxml2 library. A heap-based buffer overread could happen in xmlNextChar.

References:

https://bugzilla.gnome.org/showbug.cgi?id=759671

Upstream fix:

https://git.gnome.org/browse/libxml2/commit/?id=a7a94612aa3b16779e2c74e1fa353b5d9786c602