The go command may generate unexpected code at build time when using cgo. This may result in unexpected behavior when running a go program which uses cgo. This may occur when running an untrusted module which contains directories with newline characters in their names. Modules which are retrieved using the go command, i.e. via "go get", are not affected (modules retrieved using GOPATH-mode, i.e. GO111MODULE=off, may be affected).
Excessive resource consumption in net/http, net/textproto and mime/multipart
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 combi
Incorrect calculation on P256 curves in crypto/internal/nistec
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.
Denial of service via crafted HTTP/2 stream in net/http and golang.org/x/net
A maliciously crafted HTTP/2 stream could cause excessive CPU consumption in the HPACK decoder, sufficient to cause a denial of service from a small number of small requests.
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 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
Unsanitized NUL in environment variables on Windows in syscall and os/exec
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".
Memory exhaustion when compiling regular expressions in regexp/syntax
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.
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.
In archive/zip in Go before 1.16.8 and 1.17.x before 1.17.1, a crafted archive header (falsely designating that many files are present) can cause a NewReader or OpenReader panic. NOTE: this issue exists because of an incomplete fix for CVE-2021-33196.
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.
Go before 1.16.9 and 1.17.x before 1.17.2 has a Buffer Overflow via large arguments in a function invocation from a WASM module, when GOARCH=wasm GOOS=js is used.
Go before 1.17 does not properly consider extraneous zero characters at the beginning of an IP address octet, which (in some situations) allows attackers to bypass access control that is based on IP addresses, because of unexpected octal interpretation. This affects net.ParseIP and net.ParseCIDR.
In Go before 1.15.13 and 1.16.x before 1.16.5, some configurations of ReverseProxy (from net/http/httputil) result in a situation where an attacker is able to drop arbitrary headers.
Go before 1.15.13 and 1.16.x before 1.16.5 has functions for DNS lookups that do not validate replies from DNS servers, and thus a return value may contain an unsafe injection (e.g., XSS) that does not conform to the RFC1035 format.