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GHSA-p747-qc5p-773r
No affected components available
Summary
Any user that has enabled 2FA can have their TOTP reused during the standard 30 second validity window.
Details
The below code is called when a user that has 2FA is authenticating to the application. Once they submit a valid username-password-totp combination, the user gets authenticated. If that same TOTP is used for the same user's account again within the validity window, it will allow the other session to authenticate successfully.
Source: <ins>pkg/user/totp.go:128</ins>
// ValidateTOTPPasscode validated totp codes of users.
func ValidateTOTPPasscode(s *xorm.Session, passcode *TOTPPasscode) (t *TOTP, err error) {
t, err = GetTOTPForUser(s, passcode.User)
if err != nil {
return
}
if !totp.Validate(passcode.Passcode, t.Secret) {
return nil, ErrInvalidTOTPPasscode{Passcode: passcode.Passcode}
}
return
}
Section 6.5.1 within the Authentication section of the OWASP ASVS recommends multiple checks, some of which involving TOTPs:
Verify that lookup secrets, out-of-band authentication requests or codes, and time-based one-time passwords (TOTPs) are only successfully usable once.
The OWASP WSTG also references this as one of their checks to look for:
Can the OTPs be used more than once?
PoC
https://github.com/user-attachments/assets/19d3b4c3-c219-4f59-b57d-45c9f6a264c8
Impact
Any user who uses 2FA could be impacted if their traffic is able to be captured, they're phished/social engineered, or other methods of attack. This disrupts one layer of the defense-in-depth model surrounding 2FA.
Similar CVEs
Remediation
Store a deny-list of TOTP codes for their validity windows and check submitted codes against it to ensure none are being reused. After their validity window has closed, the 2FA code can be removed from the list.
The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker needs basic access or low-level privileges. The attacker needs the user to perform some action, like clicking a link. The impact is confined to the system where the vulnerability exists. There is a high impact on the confidentiality of the information.
Exploitation attempts have been detected. Elevated vigilance and prompt remediation are advised.
The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.
We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.
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