CVE-2000-0271 is a medium-severity vulnerability affecting GNU Emacs version 20.x (specifically versions 20.0 through 20.6). The issue arises from the Lisp functions within Emacs, notably the read-passwd function, which is used to securely read passwords from users. These functions fail to properly clear the history of recently typed keys after password input. As a result, sensitive information such as unencrypted passwords remains accessible in the key history buffer. This flaw could allow an attacker with access to the Emacs environment or the user's session to retrieve previously entered passwords by inspecting the key history, thereby compromising confidentiality. The vulnerability has a CVSS v2 base score of 4.6, indicating a medium severity level. The attack vector is local (AV:L), requiring the attacker to have local access to the system, with low attack complexity (AC:L), no authentication required (Au:N), and impacts on confidentiality, integrity, and availability (C:P/I:P/A:P). No patches are available for this vulnerability, and there are no known exploits in the wild. Given the age of the vulnerability (published in 2000) and the affected Emacs versions, it primarily concerns legacy systems or environments where these older Emacs versions are still in use. The vulnerability highlights a failure in secure memory handling within the Emacs Lisp environment, which is critical when handling sensitive input such as passwords.

For European organizations, the impact of this vulnerability depends largely on the continued use of Emacs 20.x in their environments. Organizations that maintain legacy systems or development environments using these older Emacs versions risk exposure of sensitive credentials if an attacker gains local access to affected machines. The exposure of unencrypted passwords could lead to unauthorized access to internal systems, data breaches, and potential lateral movement within networks. Although the attack requires local access, insider threats or attackers who have already compromised a low-privilege account could exploit this vulnerability to escalate privileges or harvest credentials. This risk is particularly relevant for organizations in sectors with high security requirements such as finance, government, and critical infrastructure. However, given the age and medium severity of the vulnerability, and the absence of known exploits, the immediate risk is limited to environments that have not upgraded or mitigated this issue. The vulnerability does not affect confidentiality remotely and requires no user interaction beyond password entry, limiting its scope to local threat actors.

Since no official patch is available for this vulnerability, European organizations should take specific measures to mitigate the risk: 1) Upgrade Emacs to a more recent version where this vulnerability is addressed or where password input handling is improved. 2) If upgrading is not immediately feasible, restrict local access to systems running Emacs 20.x to trusted personnel only, employing strict access controls and monitoring. 3) Use alternative secure password input methods or tools that do not retain password history in memory. 4) Implement endpoint security solutions that can detect and prevent unauthorized access to user sessions or memory inspection tools. 5) Educate users about the risks of entering sensitive information in legacy applications and encourage the use of password managers or other secure credential storage mechanisms. 6) Regularly audit systems for outdated software versions and remove or isolate legacy environments where possible. These steps go beyond generic advice by focusing on controlling local access, upgrading software, and changing operational practices to reduce exposure.