Vulnerabilities (CVE)

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". ... 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.

Show More

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).

A path traversal vulnerability exists in filepath.Clean on Windows. On Windows, the filepath.Clean function could transform an invalid path such as "a/../c:/b" into the valid path "c:\b". This transformation of a relative (if invalid) path into an absolute path could enable a directory traversal attack. After fix, the filepath.Clean function transforms this path into the relative (but still invalid) path ".\c:\b".

An attacker can cause excessive memory growth in a Go server accepting HTTP/2 requests. HTTP/2 server connections contain a cache of HTTP header keys sent by the client. While the total number of entries in this cache is capped, an attacker sending very large keys can cause the server to allocate approximately 64 MiB per open connection.

Due to unsanitized NUL values, attackers may be able to maliciously set environment variables on Windows. In syscall.StartProcess and os/exec.Cmd, invalid environment variable values containing NUL values are not properly checked for. A malicious environment variable value can exploit this behavior to set a value for a different environment variable. For example, the environment variable string "A=B\x00C=D" sets the variables "A=B" and "C=D".

Programs which compile regular expressions from untrusted sources may be vulnerable to memory exhaustion or denial of service. The parsed regexp representation is linear in the size of the input, but in some cases the constant factor can be as high as 40,000, making relatively small regexps consume much larger amounts of memory. After fix, each regexp being parsed is limited to a 256 MB memory footprint. Regular expressions whose representation would use more space than that are rejected. Normal ... Programs which compile regular expressions from untrusted sources may be vulnerable to memory exhaustion or denial of service. The parsed regexp representation is linear in the size of the input, but in some cases the constant factor can be as high as 40,000, making relatively small regexps consume much larger amounts of memory. After fix, each regexp being parsed is limited to a 256 MB memory footprint. Regular expressions whose representation would use more space than that are rejected. Normal use of regular expressions is unaffected.

Show More

JoinPath and URL.JoinPath do not remove ../ path elements appended to a relative path. For example, JoinPath("https://go.dev", "../go") returns the URL "https://go.dev/../go", despite the JoinPath documentation stating that ../ path elements are removed from the result.

A too-short encoded message can cause a panic in Float.GobDecode and Rat GobDecode in math/big in Go before 1.17.13 and 1.18.5, potentially allowing a denial of service.

Improper exposure of client IP addresses in net/http before Go 1.17.12 and Go 1.18.4 can be triggered by calling httputil.ReverseProxy.ServeHTTP with a Request.Header map containing a nil value for the X-Forwarded-For header, which causes ReverseProxy to set the client IP as the value of the X-Forwarded-For header.

Uncontrolled recursion in Decoder.Decode in encoding/gob before Go 1.17.12 and Go 1.18.4 allows an attacker to cause a panic due to stack exhaustion via a message which contains deeply nested structures.

Infinite loop in Read in crypto/rand before Go 1.17.11 and Go 1.18.3 on Windows allows attacker to cause an indefinite hang by passing a buffer larger than 1 << 32 - 1 bytes.

Uncontrolled recursion in Unmarshal in encoding/xml before Go 1.17.12 and Go 1.18.4 allows an attacker to cause a panic due to stack exhaustion via unmarshalling an XML document into a Go struct which has a nested field that uses the 'any' field tag.

Uncontrolled recursion in Glob in path/filepath before Go 1.17.12 and Go 1.18.4 allows an attacker to cause a panic due to stack exhaustion via a path containing a large number of path separators.

Uncontrolled recursion in Glob in io/fs before Go 1.17.12 and Go 1.18.4 allows an attacker to cause a panic due to stack exhaustion via a path which contains a large number of path separators.

Non-random values for ticket_age_add in session tickets in crypto/tls before Go 1.17.11 and Go 1.18.3 allow an attacker that can observe TLS handshakes to correlate successive connections by comparing ticket ages during session resumption.

Code injection in Cmd.Start in os/exec before Go 1.17.11 and Go 1.18.3 allows execution of any binaries in the working directory named either "..com" or "..exe" by calling Cmd.Run, Cmd.Start, Cmd.Output, or Cmd.CombinedOutput when Cmd.Path is unset.

Requests forwarded by ReverseProxy include the raw query parameters from the inbound request, including unparsable parameters rejected by net/http. This could permit query parameter smuggling when a Go proxy forwards a parameter with an unparsable value. After fix, ReverseProxy sanitizes the query parameters in the forwarded query when the outbound request's Form field is set after the ReverseProxy. Director function returns, indicating that the proxy has parsed the query parameters. Proxies whi ... Requests forwarded by ReverseProxy include the raw query parameters from the inbound request, including unparsable parameters rejected by net/http. This could permit query parameter smuggling when a Go proxy forwards a parameter with an unparsable value. After fix, ReverseProxy sanitizes the query parameters in the forwarded query when the outbound request's Form field is set after the ReverseProxy. Director function returns, indicating that the proxy has parsed the query parameters. Proxies which do not parse query parameters continue to forward the original query parameters unchanged.

Show More

Reader.Read does not set a limit on the maximum size of file headers. A maliciously crafted archive could cause Read to allocate unbounded amounts of memory, potentially causing resource exhaustion or panics. After fix, Reader.Read limits the maximum size of header blocks to 1 MiB.

Incorrect conversion of certain invalid paths to valid, absolute paths in Clean in path/filepath before Go 1.17.11 and Go 1.18.3 on Windows allows potential directory traversal attack.

Go before 1.17.10 and 1.18.x before 1.18.2 has Incorrect Privilege Assignment. When called with a non-zero flags parameter, the Faccessat function could incorrectly report that a file is accessible.

The generic P-256 feature in crypto/elliptic in Go before 1.17.9 and 1.18.x before 1.18.1 allows a panic via long scalar input.

Uncontrolled recursion in Decoder.Skip in encoding/xml before Go 1.17.12 and Go 1.18.4 allows an attacker to cause a panic due to stack exhaustion via a deeply nested XML document.

In net/http in Go before 1.18.6 and 1.19.x before 1.19.1, attackers can cause a denial of service because an HTTP/2 connection can hang during closing if shutdown were preempted by a fatal error.

Certificate.Verify in crypto/x509 in Go 1.18.x before 1.18.1 can be caused to panic on macOS when presented with certain malformed certificates. This allows a remote TLS server to cause a TLS client to panic.

The golang.org/x/crypto/ssh package before 0.0.0-20220314234659-1baeb1ce4c0b for Go allows an attacker to crash a server in certain circumstances involving AddHostKey.

regexp.Compile in Go before 1.16.15 and 1.17.x before 1.17.8 allows stack exhaustion via a deeply nested expression.

encoding/pem in Go before 1.17.9 and 1.18.x before 1.18.1 has a Decode stack overflow via a large amount of PEM data.

Curve.IsOnCurve in crypto/elliptic in Go before 1.16.14 and 1.17.x before 1.17.7 can incorrectly return true in situations with a big.Int value that is not a valid field element.

cmd/go in Go before 1.16.14 and 1.17.x before 1.17.7 can misinterpret branch names that falsely appear to be version tags. This can lead to incorrect access control if an actor is supposed to be able to create branches but not tags.

Rat.SetString in math/big in Go before 1.16.14 and 1.17.x before 1.17.7 has an overflow that can lead to Uncontrolled Memory Consumption.

Uncontrolled recursion in the Parse functions in go/parser before Go 1.17.12 and Go 1.18.4 allow an attacker to cause a panic due to stack exhaustion via deeply nested types or declarations.

Acceptance of some invalid Transfer-Encoding headers in the HTTP/1 client in net/http before Go 1.17.12 and Go 1.18.4 allows HTTP request smuggling if combined with an intermediate server that also improperly fails to reject the header as invalid.

Go before 1.16.12 and 1.17.x before 1.17.5 on UNIX allows write operations to an unintended file or unintended network connection as a consequence of erroneous closing of file descriptor 0 after file-descriptor exhaustion.

net/http in Go before 1.16.12 and 1.17.x before 1.17.5 allows uncontrolled memory consumption in the header canonicalization cache via HTTP/2 requests.

The x/crypto/ssh package before 0.0.0-20211202192323-5770296d904e of golang.org/x/crypto allows an attacker to panic an SSH server.

Go before 1.16.10 and 1.17.x before 1.17.3 allows an archive/zip Reader.Open panic via a crafted ZIP archive containing an invalid name or an empty filename field.

ImportedSymbols in debug/macho (for Open or OpenFat) in Go before 1.16.10 and 1.17.x before 1.17.3 Accesses a Memory Location After the End of a Buffer, aka an out-of-bounds slice situation.

An issue was discovered in GoGo Protobuf before 1.3.2. plugin/unmarshal/unmarshal.go lacks certain index validation, aka the "skippy peanut butter" issue.

Go before 1.14.14 and 1.15.x before 1.15.7 on Windows is vulnerable to Command Injection and remote code execution when using the "go get" command to fetch modules that make use of cgo (for example, cgo can execute a gcc program from an untrusted download).

In Go before 1.14.14 and 1.15.x before 1.15.7, crypto/elliptic/p224.go can generate incorrect outputs, related to an underflow of the lowest limb during the final complete reduction in the P-224 field.