A flaw was found in rsync which could be triggered when rsync compares file checksums. This flaw allows an attacker to manipulate the checksum length (s2length) to cause a comparison between a checksum and uninitialized memory and leak one byte of uninitialized stack data at a time.

A flaw was found in rsync. It could allow a server to enumerate the contents of an arbitrary file from the client's machine. This issue occurs when files are being copied from a client to a server. During this process, the rsync server will send checksums of local data to the client to compare with in order to determine what data needs to be sent to the server. By sending specially constructed checksum values for arbitrary files, an attacker may be able to reconstruct the data of those files byte-by-byte based on the responses from the client.

crypto: algifaead - Revert to operating out-of-place

A security regression (CVE-2006-5051) was discovered in OpenSSH's server (sshd). There is a race condition which can lead sshd to handle some signals in an unsafe manner. An unauthenticated, remote attacker may be able to trigger it by failing to authenticate within a set time period.

A flaw was found in grub2. When reading data from a squash4 filesystem, grub's squash4 fs module uses user-controlled parameters from the filesystem geometry to determine the internal buffer size, however, it improperly checks for integer overflows. A maliciously crafted filesystem may lead some of those buffer size calculations to overflow, causing it to perform a grubmalloc() operation with a smaller size than expected. As a result, the directread() will perform a heap based out-of-bounds write during data reading. This flaw may be leveraged to corrupt grub's internal critical data and may result in arbitrary code execution, by-passing secure boot protections.

HTTP/2 Rapid reset attack The HTTP/2 protocol allows clients to indicate to the server that a previous stream should be canceled by sending a RSTSTREAM frame. The protocol does not require the client and server to coordinate the cancellation in any way, the client may do it unilaterally. The client may also assume that the cancellation will take effect immediately when the server receives the RSTSTREAM frame, before any other data from that TCP connection is processed.

Abuse of this feature is called a Rapid Reset attack because it relies on the ability for an endpoint to send a RSTSTREAM frame immediately after sending a request frame, which makes the other endpoint start working and then rapidly resets the request. The request is canceled, but leaves the HTTP/2 connection open.

The HTTP/2 Rapid Reset attack built on this capability is simple: The client opens a large number of streams at once as in the standard HTTP/2 attack, but rather than waiting for a response to each request stream from the server or proxy, the client cancels each request immediately.

The ability to reset streams immediately allows each connection to have an indefinite number of requests in flight. By explicitly canceling the requests, the attacker never exceeds the limit on the number of concurrent open streams. The number of in-flight requests is no longer dependent on the round-trip time (RTT), but only on the available network bandwidth.

In a typical HTTP/2 server implementation, the server will still have to do significant amounts of work for canceled requests, such as allocating new stream data structures, parsing the query and doing header decompression, and mapping the URL to a resource. For reverse proxy implementations, the request may be proxied to the backend server before the RSTSTREAM frame is processed. The client on the other hand paid almost no costs for sending the requests. This creates an exploitable cost asymmetry between the server and the client.

Multiple software artifacts implementing HTTP/2 are affected. This advisory was originally ingested from the swift-nio-http2 repo advisory and their original conent follows.

swift-nio-http2 specific advisory swift-nio-http2 is vulnerable to a denial-of-service vulnerability in which a malicious client can create and then reset a large number of HTTP/2 streams in a short period of time. This causes swift-nio-http2 to commit to a large amount of expensive work which it then throws away, including creating entirely new Channels to serve the traffic. This can easily overwhelm an EventLoop and prevent it from making forward progress.

swift-nio-http2 1.28 contains a remediation for this issue that applies reset counter using a sliding window. This constrains the number of stream resets that may occur in a given window of time. Clients violating this limit will have their connections torn down. This allows clients to continue to cancel streams for legitimate reasons, while constraining malicious actors.

A vulnerability was found in OpenSSH when the VerifyHostKeyDNS option is enabled. A machine-in-the-middle attack can be performed by a malicious machine impersonating a legit server. This issue occurs due to how OpenSSH mishandles error codes in specific conditions when verifying the host key. For an attack to be considered successful, the attacker needs to manage to exhaust the client's memory resource first, turning the attack complexity high.

A flaw was found in rsync. When using the --safe-links option, rsync fails to properly verify if a symbolic link destination contains another symbolic link within it. This results in a path traversal vulnerability, which may lead to arbitrary file write outside the desired directory.

It was found that polkit could be tricked into bypassing the credential checks for D-Bus requests, elevating the privileges of the requestor to the root user. This flaw could be used by an unprivileged local attacker to, for example, create a new local administrator. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

Kibana contain an arbitrary code execution flaw in the Timelion visualizer.

A sandbox bypass vulnerability exists in Jenkins Script Security Plugin 1.53 and earlier in src/main/java/org/jenkinsci/plugins/scriptsecurity/sandbox/groovy/GroovySandbox.java, src/main/java/org/jenkinsci/plugins/scriptsecurity/sandbox/groovy/SecureGroovyScript.java that allows attackers with Overall/Read permission to execute arbitrary code on the Jenkins master JVM.

A sandbox bypass vulnerability exists in Jenkins Pipeline: Groovy Plugin 2.63 and earlier in pom.xml, src/main/java/org/jenkinsci/plugins/workflow/cps/CpsGroovyShell.java that allows attackers able to control pipeline scripts to execute arbitrary code on the Jenkins master JVM.

Apache HTTP Server, with MPM event, worker or prefork, code executing in less-privileged child processes or threads (including scripts executed by an in-process scripting interpreter) could execute code with the privileges of the parent process (usually root) by manipulating the scoreboard.

A code execution vulnerability exists in the Stapler web framework used by Jenkins