A bug exists in the way mod_ssl handled client renegotiations. A remote attacker could send a carefully crafted request that would cause mod_ssl to enter a loop leading to a denial of service. This bug can be only triggered with Apache HTTP Server version 2.4.37 when using OpenSSL version 1.1.1 or later, due to an interaction in changes to handling of renegotiation attempts.

RSA BSAFE Micro Edition Suite versions prior to 4.0.11 (in 4.0.x series) and versions prior to 4.1.6.2 (in 4.1.x series) contain a key management error issue. A malicious TLS server could potentially cause a Denial Of Service (DoS) on TLS clients during the handshake when a very large prime value is sent to the TLS client, and an Ephemeral or Anonymous Diffie-Hellman cipher suite (DHE or ADH) is used.

Simultaneous Multi-threading (SMT) in processors can enable local users to exploit software vulnerable to timing attacks via a side-channel timing attack on 'port contention'.

The OpenSSL DSA signature algorithm has been shown to be vulnerable to a timing side channel attack. An attacker could use variations in the signing algorithm to recover the private key. Fixed in OpenSSL 1.1.1a (Affected 1.1.1). Fixed in OpenSSL 1.1.0j (Affected 1.1.0-1.1.0i). Fixed in OpenSSL 1.0.2q (Affected 1.0.2-1.0.2p).

The OpenSSL ECDSA signature algorithm has been shown to be vulnerable to a timing side channel attack. An attacker could use variations in the signing algorithm to recover the private key. Fixed in OpenSSL 1.1.0j (Affected 1.1.0-1.1.0i). Fixed in OpenSSL 1.1.1a (Affected 1.1.1).

Spring Framework, version 5.1, versions 5.0.x prior to 5.0.10, versions 4.3.x prior to 4.3.20, and older unsupported versions on the 4.2.x branch provide support for range requests when serving static resources through the ResourceHttpRequestHandler, or starting in 5.0 when an annotated controller returns an org.springframework.core.io.Resource. A malicious user (or attacker) can add a range header with a high number of ranges, or with wide ranges that overlap, or both, for a denial of service attack. This vulnerability affects applications that depend on either spring-webmvc or spring-webflux. Such applications must also have a registration for serving static resources (e.g. JS, CSS, images, and others), or have an annotated controller that returns an org.springframework.core.io.Resource. Spring Boot applications that depend on spring-boot-starter-web or spring-boot-starter-webflux are ready to serve static resources out of the box and are therefore vulnerable.

In Apache HTTP Server 2.4.17 to 2.4.34, by sending continuous, large SETTINGS frames a client can occupy a connection, server thread and CPU time without any connection timeout coming to effect. This affects only HTTP/2 connections. A possible mitigation is to not enable the h2 protocol.

RSA BSAFE Micro Edition Suite, version 4.1.6, contains an integer overflow vulnerability. A remote attacker could use maliciously constructed ASN.1 data to potentially cause a Denial Of Service.

RSA BSAFE Micro Edition Suite, prior to 4.1.6.1 (in 4.1.x), and RSA BSAFE Crypto-C Micro Edition versions prior to 4.0.5.3 (in 4.0.x) contain an Uncontrolled Resource Consumption ('Resource Exhaustion') vulnerability when parsing ASN.1 data. A remote attacker could use maliciously constructed ASN.1 data that would exhaust the stack, potentially causing a Denial Of Service.

RSA BSAFE Micro Edition Suite, versions prior to 4.0.11 (in 4.0.x) and prior to 4.1.6.1 (in 4.1.x), contains an Improper Clearing of Heap Memory Before Release ('Heap Inspection') vulnerability. Decoded PKCS #12 data in heap memory is not zeroized by MES before releasing the memory internally and a malicious local user could gain access to the unauthorized data by doing heap inspection.