An OpenSSL TLS server may crash if sent a maliciously crafted renegotiation ClientHello message from a client. If a TLSv1.2 renegotiation ClientHello omits the signaturealgorithms extension (where it was present in the initial ClientHello), but includes a signaturealgorithmscert extension then a NULL pointer dereference will result, leading to a crash and a denial of service attack. A server is only vulnerable if it has TLSv1.2 and renegotiation enabled (which is the default configuration). OpenSSL TLS clients are not impacted by this issue. All OpenSSL 1.1.1 versions are affected by this issue. Users of these versions should upgrade to OpenSSL 1.1.1k. OpenSSL 1.0.2 is not impacted by this issue. Fixed in OpenSSL 1.1.1k (Affected 1.1.1-1.1.1j).

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

Affected devices do not properly sanitize data introduced by an user when rendering the web interface. This could allow an authenticated remote attacker with administrative privileges to inject code and lead to a DOM-based XSS.

Affected devices do not properly handle the renegotiation of SSL/TLS parameters. This could allow an unauthenticated remote attacker to bypass the TCP brute force prevention and lead to a denial of service condition for the duration of the attack.

Affected devices do not properly sanitize an input field. This could allow an authenticated remote attacker with administrative privileges to inject code or spawn a system root shell.

Affected devices contain a vulnerability that allows an unauthenticated attacker to trigger a denial of service condition. The vulnerability can be triggered if a large amount of DCP reset packets are sent to the device.

Heap-based buffer overflow in dnsmasq before 2.78 allows remote attackers to cause a denial of service (crash) or execute arbitrary code via a crafted DNS response.

A flaw in ICMP packets in the Linux kernel may allow an attacker to quickly scan open UDP ports. This flaw allows an off-path remote attacker to effectively bypass source port UDP randomization. Software that relies on UDP source port randomization are indirectly affected as well on the Linux Based Products (RUGGEDCOM RM1224: All versions between v5.0 and v6.4, SCALANCE M-800: All versions between v5.0 and v6.4, SCALANCE S615: All versions between v5.0 and v6.4, SCALANCE SC-600: All versions prior to v2.1.3, SCALANCE W1750D: v8.3.0.1, v8.6.0, and v8.7.0, SIMATIC Cloud Connect 7: All versions, SIMATIC MV500 Family: All versions, SIMATIC NET CP 1243-1 (incl. SIPLUS variants): Versions 3.1.39 and later, SIMATIC NET CP 1243-7 LTE EU: Version

Specially crafted PROFINET DCP packets sent on a local Ethernet segment (Layer 2) to an affected product could cause a denial of service condition of that product. Human interaction is required to recover the system. PROFIBUS interfaces are not affected.

Specially crafted PROFINET DCP broadcast packets could cause a denial of service condition of affected products on a local Ethernet segment (Layer 2). Human interaction is required to recover the systems. PROFIBUS interfaces are not affected.

The integrated web server on Siemens SCALANCE M-800 and S615 modules with firmware before 4.02 does not set the secure flag for the session cookie in an https session, which makes it easier for remote attackers to capture this cookie by intercepting its transmission within an http session.

Profinet-IO (PNIO) stack versions prior V06.00 do not properly limit internal resource allocation when multiple legitimate diagnostic package requests are sent to the DCE-RPC interface. This could lead to a denial of service condition due to lack of memory for devices that include a vulnerable version of the stack.

The security vulnerability could be exploited by an attacker with network access to an affected device. Successful exploitation requires no system privileges and no user interaction. An attacker could use the vulnerability to compromise the availability of the device.

A vulnerability has been identified in RUGGEDCOM RM1224 (V6.3), SCALANCE M-800 (V6.3), SCALANCE S615 (V6.3), SCALANCE SC-600 (All Versions >= V2.1 and < V2.1.3). Multiple failed SSH authentication attempts could trigger a temporary Denial-of-Service under certain conditions. When triggered, the device will reboot automatically.