Using go get to fetch a module with the ".git" suffix may unexpectedly fallback to the insecure "git://" protocol if the module is unavailable via the secure "https://" and "git+ssh://" protocols, even if GOINSECURE is not set for said module. This only affects users who are not using the module proxy and are fetching modules directly (i.e. GOPROXY=off).
Before Go 1.20, the RSA based TLS key exchanges used the math/big library, which is not constant time. RSA blinding was applied to prevent timing attacks, but analysis shows this may not have been fully effective. In particular it appears as if the removal of PKCS#1 padding may leak timing information, which in turn could be used to recover session key bits. In Go 1.20, the crypto/tls library switched to a fully constant time RSA implementation, which we do not believe exhibits any timing side channels.
The filepath package does not recognize paths with a \??\ prefix as special. On Windows, a path beginning with \??\ is a Root Local Device path equivalent to a path beginning with \\?\. Paths with a \??\ prefix may be used to access arbitrary locations on the system. For example, the path \??\c:\x is equivalent to the more common path c:\x. Before fix, Clean could convert a rooted path such as \a\..\??\b into the root local device path \??\b. Clean will now convert this to .\??\b. Similarly, Join(\, ??, b) could convert a seemingly innocent sequence of path elements into the root local device path \??\b. Join will now convert this to \.\??\b. In addition, with fix, IsAbs now correctly reports paths beginning with \??\ as absolute, and VolumeName correctly reports the \??\ prefix as a volume name. UPDATE: Go 1.20.11 and Go 1.21.4 inadvertently changed the definition of the volume name in Windows paths starting with \?, resulting in filepath.Clean(\?\c:) returning \?\c: rather than \?\c:\ (among other effects). The previous behavior has been restored.
On Windows, The IsLocal function does not correctly detect reserved device names in some cases. Reserved names followed by spaces, such as "COM1 ", and reserved names "COM" and "LPT" followed by superscript 1, 2, or 3, are incorrectly reported as local. With fix, IsLocal now correctly reports these names as non-local.
pkg/suci/suci.go in free5GC udm before 1.2.0, when Go before 1.19 is used, allows an Invalid Curve Attack because it may compute a shared secret via an uncompressed public key that has not been validated. An attacker can send arbitrary SUCIs to the UDM, which tries to decrypt them via both its private key and the attacker's public key.
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.
Line directives ("//line") can be used to bypass the restrictions on "//go:cgo_" directives, allowing blocked linker and compiler flags to be passed during compilation. This can result in unexpected execution of arbitrary code when running "go build". The line directive requires the absolute path of the file in which the directive lives, which makes exploiting this issue significantly more complex.
The html/template package does not properly handle HTML-like "" comment tokens, nor hashbang "#!" comment tokens, in <script> contexts. This may cause the template parser to improperly interpret the contents of <script> contexts, causing actions to be improperly escaped. This may be leveraged to perform an XSS attack.
The html/template package does not apply the proper rules for handling occurrences of "<script", "<!--", and "</script" within JS literals in <script> contexts. This may cause the template parser to improperly consider script contexts to be terminated early, causing actions to be improperly escaped. This could be leveraged to perform an XSS attack.
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.