CVE-2026-81705 in openssl_encrypt
Summary
by MITRE • 08/27/2026
openssl-encrypt before 1.4.9 fails to redact the file password in its --debug argv dump when the password is supplied via bundled short-option spellings (e.g. -apHunter2) or abbreviated long-option spellings (e.g. --passw). The sanitizer only recognized exact option names, --option=value forms, and tokens starting with -p, so these spellings bypass the redaction chokepoint and the cleartext password is written to stderr. Anyone with access to that output (terminal scrollback, merged 2>&1 output, CI job logs, or the GUI's persistent debug log) can recover the password.
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Analysis
by VulDB Data Team • 08/27/2026
The OpenSSL encryption utility contains a critical information disclosure vulnerability in versions prior to 1.4.9 regarding the handling of command-line arguments during debugging operations. This flaw specifically affects the sanitization logic that is designed to prevent sensitive credentials from being written to standard error output when the debug flag is enabled. The core issue stems from an incomplete implementation of pattern matching within the argument parser, which fails to recognize certain valid but non-standard ways users might supply their encryption passwords via command-line options.
The technical root cause lies in the rigid definition of recognized option formats used by the password sanitizer. The existing logic correctly identifies and redacts passwords when they are provided using exact long-form option names such as --passphrase, or through key-value pair syntax like --option=value. It also successfully masks passwords passed via short options that begin with -p followed immediately by a single character flag, such as -paPassword. However, the implementation fails to account for two common alternative spellings: concatenated short-option strings where multiple flags are combined into one argument without spaces, and abbreviated long-form option names that do not match the full canonical string exactly.
When an operator supplies a password using a bundled short-option spelling, such as -apHunter2, or an abbreviated long-option like --passw=Hunter2, the sanitizer does not trigger its redaction mechanism because these inputs fall outside the predefined whitelist of recognized patterns. Consequently, the cleartext password is included in the debug output stream rather than being masked with placeholder characters. This behavior represents a classic case of insufficient input validation leading to sensitive data exposure, aligning closely with CWE-209 which describes the generation of error messages containing sensitive information that could be exploited by attackers.
The operational impact of this vulnerability is significant for any environment where debug logging is enabled or accessible. Since OpenSSL tools are frequently used in automated scripts and continuous integration pipelines, it is common practice to capture both standard output and standard error into log files using redirection operators like 2>&1. In such scenarios, the unredacted password becomes permanently recorded in plain text within CI job logs, terminal scrollbacks, or persistent debug archives maintained by graphical user interfaces. This creates a high-risk vector for credential theft, as any individual with read access to these logs can immediately recover the encryption key material without needing further exploitation steps.
This vulnerability maps directly to MITRE ATT&CK technique T1505.003, which involves Server Software Component: Stored Remote Logs. Attackers who gain access to system logs or CI/CD artifacts can extract credentials stored in plaintext due to this logging flaw. The severity is heightened by the fact that encryption keys are often used for long-term data protection, meaning compromised passwords could lead to persistent unauthorized access even after initial detection if key rotation has not occurred.
Mitigation strategies must prioritize immediate software updates and operational adjustments. Users running OpenSSL versions before 1.4.9 should upgrade to the latest patched release where this sanitization logic has been corrected to handle all valid argument permutations. For environments that cannot immediately patch, disabling debug output in production or automated pipeline contexts is essential to prevent log leakage. Additionally, organizations should implement strict access controls on log storage systems and consider using external secret management solutions rather than passing passwords via command-line arguments whenever possible, thereby reducing the attack surface regardless of software version status.