CVE-2021-3882 Sensitive Cookie in HTTPS Session Without 'Secure' Attribute in ledgersmb/ledgersmb
Attackers can steal session cookies via HTTP traffic if the server is behind a reverse proxy without Secure attribute, leading to account takeover.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2021-3882?
CVE-2021-3882 is a medium-severity vulnerability in ledgersmb/ledgersmb, published on 14 Oct 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
LedgerSMB does not set the 'Secure' attribute on the session authorization cookie when the client uses HTTPS and the LedgerSMB server is behind a reverse proxy. By tricking a user to use an unencrypted connection (HTTP), an attacker may be able to obtain the authentication data by capturing network traffic. LedgerSMB 1.8 and newer switched from Basic authentication to using cookie authentication with encrypted cookies. Although an attacker can't access the information inside the cookie, nor the password of the user, possession of the cookie is enough to access the application as the user from which the cookie has been obtained. In order for the attacker to obtain the cookie, first of all the server must be configured to respond to unencrypted requests, the attacker must be suitably positioned to eavesdrop on the network traffic between the client and the server *and* the user must be tricked into using unencrypted HTTP traffic. Proper audit control and separation of duties limit Integrity impact of the attack vector. Users of LedgerSMB 1.8 are urged to upgrade to known-fixed versions. Users of LedgerSMB 1.7 or 1.9 are unaffected by this vulnerability and don't need to take action. As a workaround, users may configure their Apache or Nginx reverse proxy to add the Secure attribute at the network boundary instead of relying on LedgerSMB. For Apache, please refer to the 'Header always edit' configuration command in the mod_headers module. For Nginx, please refer to the 'proxy_cookie_flags' configuration command.
Which versions are affected by CVE-2021-3882?
It affects 1 product.
Products include Ledgersmb Ledgersmb.
How do I fix CVE-2021-3882?
Upgrade to a fixed version.
Is CVE-2021-3882 being exploited?
There is no known exploitation of CVE-2021-3882 in the wild and no public exploit code.
Other vulnerabilities in ledgersmb/ledgersmb
Sources
Also known as GHSA-q34c-v76q-8jx6, UBUNTU-CVE-2021-3882.