golang-1.19.13-1.el9, go-toolset-1.19.13-1.el9

Go Toolset provides the Go programming language tools and libraries. Go is alternatively known as golang.

The golang packages provide the Go programming language compiler.

Security Fix(es):

* golang: net/http, x/net/http2: rapid stream resets can cause excessive work [CVE-2023-44487] (CVE-2023-39325)
* HTTP/2: Multiple HTTP/2 enabled web servers are vulnerable to a DDoS attack (Rapid Reset Attack) (CVE-2023-44487)
* golang: crypto/tls: slow verification of certificate chains containing large RSA keys (CVE-2023-29409)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Bug Fix(es):

* Midstream dist-git patches (BZ#2223637)

CVE-2023-29409
Extremely large RSA keys in certificate chains can cause a client/server to expend significant CPU time verifying signatures. With fix, the size of RSA keys transmitted during handshakes is restricted to <= 8192 bits. Based on a survey of publicly trusted RSA keys, there are currently only three certificates in circulation with keys larger than this, and all three appear to be test certificates that are not actively deployed. It is possible there are larger keys in use in private PKIs, but we target the web PKI, so causing breakage here in the interests of increasing the default safety of users of crypto/tls seems reasonable.
CVE-2023-39325
A malicious HTTP/2 client which rapidly creates requests and immediately resets them can cause excessive server resource consumption. While the total number of requests is bounded by the http2.Server.MaxConcurrentStreams setting, resetting an in-progress request allows the attacker to create a new request while the existing one is still executing. With the fix applied, HTTP/2 servers now bound the number of simultaneously executing handler goroutines to the stream concurrency limit (MaxConcurrentStreams). New requests arriving when at the limit (which can only happen after the client has reset an existing, in-flight request) will be queued until a handler exits. If the request queue grows too large, the server will terminate the connection. This issue is also fixed in golang.org/x/net/http2 for users manually configuring HTTP/2. The default stream concurrency limit is 250 streams (requests) per HTTP/2 connection. This value may be adjusted using the golang.org/x/net/http2 package; see the Server.MaxConcurrentStreams setting and the ConfigureServer function.
CVE-2023-44487
The HTTP/2 protocol allows a denial of service (server resource consumption) because request cancellation can reset many streams quickly, as exploited in the wild in August through October 2023.