Detections
Analytics
Amazon Linux 2023 : amazon-cloudwatch-agent (ALAS2023-2024-498)
medium Nessus Plugin ID 189342
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Synopsis
The remote Amazon Linux 2023 host is missing a security update.Description
It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2023-2024-498 advisory.- 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-2023-39325)
- A malicious HTTP sender can use chunk extensions to cause a receiver reading from a request or response body to read many more bytes from the network than are in the body. A malicious HTTP client can further exploit this to cause a server to automatically read a large amount of data (up to about 1GiB) when a handler fails to read the entire body of a request. Chunk extensions are a little-used HTTP feature which permit including additional metadata in a request or response body sent using the chunked encoding. The net/http chunked encoding reader discards this metadata. A sender can exploit this by inserting a large metadata segment with each byte transferred. The chunk reader now produces an error if the ratio of real body to encoded bytes grows too small. (CVE-2023-39326)
- OpenTelemetry-Go Contrib is a collection of third-party packages for OpenTelemetry-Go. A handler wrapper out of the box adds labels `http.user_agent` and `http.method` that have unbound cardinality. It leads to the server's potential memory exhaustion when many malicious requests are sent to it. HTTP header User- Agent or HTTP method for requests can be easily set by an attacker to be random and long. The library internally uses `httpconv.ServerRequest` that records every value for HTTP `method` and `User-Agent`. In order to be affected, a program has to use the `otelhttp.NewHandler` wrapper and not filter any unknown HTTP methods or User agents on the level of CDN, LB, previous middleware, etc. Version 0.44.0 fixed this issue when the values collected for attribute `http.request.method` were changed to be restricted to a set of well-known values and other high cardinality attributes were removed. As a workaround to stop being affected, `otelhttp.WithFilter()` can be used, but it requires manual careful configuration to not log certain requests entirely. For convenience and safe usage of this library, it should by default mark with the label `unknown` non-standard HTTP methods and User agents to show that such requests were made but do not increase cardinality. In case someone wants to stay with the current behavior, library API should allow to enable it. (CVE-2023-45142)
- OpenTelemetry-Go Contrib is a collection of third-party packages for OpenTelemetry-Go. Prior to version 0.46.0, the grpc Unary Server Interceptor out of the box adds labels `net.peer.sock.addr` and `net.peer.sock.port` that have unbound cardinality. It leads to the server's potential memory exhaustion when many malicious requests are sent. An attacker can easily flood the peer address and port for requests. Version 0.46.0 contains a fix for this issue. As a workaround to stop being affected, a view removing the attributes can be used. The other possibility is to disable grpc metrics instrumentation by passing `otelgrpc.WithMeterProvider` option with `noop.NewMeterProvider`. (CVE-2023-47108)
Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.
Solution
Run 'dnf update amazon-cloudwatch-agent --releasever 2023.3.20240122' to update your system.See Also
https://alas.aws.amazon.com/AL2023/ALAS-2024-498.html
https://alas.aws.amazon.com/faqs.html
https://alas.aws.amazon.com/cve/html/CVE-2023-39325.html
https://alas.aws.amazon.com/cve/html/CVE-2023-39326.html
Plugin Details
Severity: Medium
ID: 189342
File Name: al2023_ALAS2023-2024-498.nasl
Version: 1.2
Type: local
Agent: unix
Published: 1/23/2024
Updated: 3/8/2024
Supported Sensors: Agentless Assessment, Continuous Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Nessus Agent, Nessus
Risk Information
VPR
Risk Factor: Medium
Score: 4.4
CVSS v2
Risk Factor: Medium
Base Score: 5
Temporal Score: 3.7
Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:N
CVSS Score Source: CVE-2023-39326
CVSS v3
Risk Factor: Medium
Base Score: 5.3
Temporal Score: 4.6
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C
Vulnerability Information
CPE: p-cpe:/a:amazon:linux:amazon-cloudwatch-agent, cpe:/o:amazon:linux:2023
Required KB Items: Host/local_checks_enabled, Host/AmazonLinux/release, Host/AmazonLinux/rpm-list
Exploit Ease: No known exploits are available
Patch Publication Date: 1/19/2024
Vulnerability Publication Date: 10/11/2023
Reference Information
CVE: CVE-2023-39325, CVE-2023-39326, CVE-2023-45142, CVE-2023-47108
IAVB: 2023-B-0080-S, 2023-B-0096-S