Amazon Linux 2 : golang (ALAS-2023-2163)

critical Nessus Plugin ID 178816

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Synopsis

The remote Amazon Linux 2 host is missing a security update.

Description

The version of golang installed on the remote host is prior to 1.20.5-1. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2-2023-2163 advisory.

- Large handshake records may cause panics in crypto/tls. Both clients and servers may send large TLS handshake records which cause servers and clients, respectively, to panic when attempting to construct responses. This affects all TLS 1.3 clients, TLS 1.2 clients which explicitly enable session resumption (by setting Config.ClientSessionCache to a non-nil value), and TLS 1.3 servers which request client certificates (by setting Config.ClientAuth >= RequestClientCert). (CVE-2022-41724)

- A denial of service is possible from excessive resource consumption in net/http and mime/multipart.
Multipart form parsing with mime/multipart.Reader.ReadForm can consume largely unlimited amounts of memory and disk files. This also affects form parsing in the net/http package with the Request methods FormFile, FormValue, ParseMultipartForm, and PostFormValue. ReadForm takes a maxMemory parameter, and is documented as storing up to maxMemory bytes +10MB (reserved for non-file parts) in memory. File parts which cannot be stored in memory are stored on disk in temporary files. The unconfigurable 10MB reserved for non-file parts is excessively large and can potentially open a denial of service vector on its own. However, ReadForm did not properly account for all memory consumed by a parsed form, such as map entry overhead, part names, and MIME headers, permitting a maliciously crafted form to consume well over 10MB. In addition, ReadForm contained no limit on the number of disk files created, permitting a relatively small request body to create a large number of disk temporary files. With fix, ReadForm now properly accounts for various forms of memory overhead, and should now stay within its documented limit of 10MB + maxMemory bytes of memory consumption. Users should still be aware that this limit is high and may still be hazardous. In addition, ReadForm now creates at most one on-disk temporary file, combining multiple form parts into a single temporary file. The mime/multipart.File interface type's documentation states, If stored on disk, the File's underlying concrete type will be an *os.File.. This is no longer the case when a form contains more than one file part, due to this coalescing of parts into a single file. The previous behavior of using distinct files for each form part may be reenabled with the environment variable GODEBUG=multipartfiles=distinct. Users should be aware that multipart.ReadForm and the http.Request methods that call it do not limit the amount of disk consumed by temporary files. Callers can limit the size of form data with http.MaxBytesReader. (CVE-2022-41725)

- The ScalarMult and ScalarBaseMult methods of the P256 Curve may return an incorrect result if called with some specific unreduced scalars (a scalar larger than the order of the curve). This does not impact usages of crypto/ecdsa or crypto/ecdh. (CVE-2023-24532)

- Multipart form parsing can consume large amounts of CPU and memory when processing form inputs containing very large numbers of parts. This stems from several causes: 1. mime/multipart.Reader.ReadForm limits the total memory a parsed multipart form can consume. ReadForm can undercount the amount of memory consumed, leading it to accept larger inputs than intended. 2. Limiting total memory does not account for increased pressure on the garbage collector from large numbers of small allocations in forms with many parts. 3.
ReadForm can allocate a large number of short-lived buffers, further increasing pressure on the garbage collector. The combination of these factors can permit an attacker to cause an program that parses multipart forms to consume large amounts of CPU and memory, potentially resulting in a denial of service.
This affects programs that use mime/multipart.Reader.ReadForm, as well as form parsing in the net/http package with the Request methods FormFile, FormValue, ParseMultipartForm, and PostFormValue. With fix, ReadForm now does a better job of estimating the memory consumption of parsed forms, and performs many fewer short-lived allocations. In addition, the fixed mime/multipart.Reader imposes the following limits on the size of parsed forms: 1. Forms parsed with ReadForm may contain no more than 1000 parts. This limit may be adjusted with the environment variable GODEBUG=multipartmaxparts=. 2. Form parts parsed with NextPart and NextRawPart may contain no more than 10,000 header fields. In addition, forms parsed with ReadForm may contain no more than 10,000 header fields across all parts. This limit may be adjusted with the environment variable GODEBUG=multipartmaxheaders=. (CVE-2023-24536)

- Templates do not properly consider backticks (`) as Javascript string delimiters, and do not escape them as expected. Backticks are used, since ES6, for JS template literals. If a template contains a Go template action within a Javascript template literal, the contents of the action can be used to terminate the literal, injecting arbitrary Javascript code into the Go template. As ES6 template literals are rather complex, and themselves can do string interpolation, the decision was made to simply disallow Go template actions from being used inside of them (e.g. var a = {{.}}), since there is no obviously safe way to allow this behavior. This takes the same approach as github.com/google/safehtml. With fix, Template.Parse returns an Error when it encounters templates like this, with an ErrorCode of value 12. This ErrorCode is currently unexported, but will be exported in the release of Go 1.21. Users who rely on the previous behavior can re-enable it using the GODEBUG flag jstmpllitinterp=1, with the caveat that backticks will now be escaped. This should be used with caution. (CVE-2023-24538)

- Not all valid JavaScript whitespace characters are considered to be whitespace. Templates containing whitespace characters outside of the character set \t\n\f\r\u0020\u2028\u2029 in JavaScript contexts that also contain actions may not be properly sanitized during execution. (CVE-2023-24540)

- Templates containing actions in unquoted HTML attributes (e.g. attr={{.}}) executed with empty input can result in output with unexpected results when parsed due to HTML normalization rules. This may allow injection of arbitrary attributes into tags. (CVE-2023-29400)

- On Unix platforms, the Go runtime does not behave differently when a binary is run with the setuid/setgid bits. This can be dangerous in certain cases, such as when dumping memory state, or assuming the status of standard i/o file descriptors. If a setuid/setgid binary is executed with standard I/O file descriptors closed, opening any files can result in unexpected content being read or written with elevated privileges.
Similarly, if a setuid/setgid program is terminated, either via panic or signal, it may leak the contents of its registers. (CVE-2023-29403)

- The go command may execute arbitrary code at build time when using cgo. This may occur when running go get on a malicious module, or when running any other command which builds untrusted code. This is can by triggered by linker flags, specified via a #cgo LDFLAGS directive. The arguments for a number of flags which are non-optional are incorrectly considered optional, allowing disallowed flags to be smuggled through the LDFLAGS sanitization. This affects usage of both the gc and gccgo compilers. (CVE-2023-29404)

- The go command may execute arbitrary code at build time when using cgo. This may occur when running go get on a malicious module, or when running any other command which builds untrusted code. This is can by triggered by linker flags, specified via a #cgo LDFLAGS directive. Flags containing embedded spaces are mishandled, allowing disallowed flags to be smuggled through the LDFLAGS sanitization by including them in the argument of another flag. This only affects usage of the gccgo compiler. (CVE-2023-29405)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Run 'yum update golang' to update your system.

Plugin Details

Severity: Critical

ID: 178816

File Name: al2_ALAS-2023-2163.nasl

Version: 1.2

Type: local

Agent: unix

Family: Amazon Linux Local Security Checks

Published: 7/26/2023

Updated: 12/8/2023

Supported Sensors: Agentless Assessment, Continuous Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: Critical

Base Score: 10

Temporal Score: 7.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

CVSS Score Source: CVE-2023-29405

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:golang-bin, p-cpe:/a:amazon:linux:golang-src, cpe:/o:amazon:linux:2, p-cpe:/a:amazon:linux:golang-tests, p-cpe:/a:amazon:linux:golang, p-cpe:/a:amazon:linux:golang-shared, p-cpe:/a:amazon:linux:golang-docs, p-cpe:/a:amazon:linux:golang-misc

Required KB Items: Host/local_checks_enabled, Host/AmazonLinux/release, Host/AmazonLinux/rpm-list

Exploit Ease: No known exploits are available

Patch Publication Date: 7/20/2023

Vulnerability Publication Date: 2/15/2023

Reference Information

CVE: CVE-2022-41724, CVE-2022-41725, CVE-2023-24532, CVE-2023-24536, CVE-2023-24538, CVE-2023-24540, CVE-2023-29400, CVE-2023-29403, CVE-2023-29404, CVE-2023-29405

IAVB: 2023-B-0022-S, 2023-B-0029-S, 2023-B-0040-S, 2023-B-0080-S

Detections

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