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TLS 1.2 (TLS 1.2)

Security Glossary - SSL/TLS

Definition: TLS 1.2 is a widely deployed version of the Transport Layer Security protocol, defined in RFC 5246 (2008). It supports a broad range of cipher suites including both modern AEAD ciphers and older CBC-mode ciphers. TLS 1.2 remains secure when configured with strong cipher suites and is the minimum required version for PCI DSS compliance.

Why TLS 1.2 Matters

TLS 1.2 is the baseline for secure communication on the modern web. It is the minimum version required by PCI DSS for payment processing and is supported by virtually all clients still in use. While TLS 1.3 is preferred, TLS 1.2 with proper configuration remains secure.

The key to TLS 1.2 security is cipher suite configuration. TLS 1.2 supports both strong and weak cipher suites, and the server's configuration determines which are used. Weak suites like those using RC4, 3DES, or static RSA key exchange should be disabled. Only AEAD ciphers (AES-GCM, ChaCha20-Poly1305) with ECDHE key exchange should be enabled for forward secrecy.

Servers that still support TLS 1.0 or 1.1 should disable them. These versions have known vulnerabilities (BEAST, POODLE) and have been deprecated by all major browsers since 2020. The recommended configuration is TLS 1.2 and TLS 1.3 only, with a curated list of strong cipher suites.

Testing Your Configuration

An SSL checker shows which TLS versions your server accepts and lists the cipher suites offered. Verify that TLS 1.0 and 1.1 are disabled, TLS 1.2 is enabled with strong ciphers only, and ideally TLS 1.3 is also enabled.

See how your site handles TLS 1.2

Check SSL Certificate

Frequently Asked Questions

Should I disable TLS 1.2 in favor of TLS 1.3 only?
Not yet. Some enterprise clients, older mobile devices, and corporate proxies still require TLS 1.2. Disabling it would lock out these users. The recommended approach is to support both 1.2 and 1.3 with strong cipher suites.
Is TLS 1.2 vulnerable to any known attacks?
TLS 1.2 itself is not broken, but weak configurations can be. CBC mode ciphers in TLS 1.2 have had padding oracle vulnerabilities (Lucky13). Using only AEAD ciphers (AES-GCM) and ECDHE key exchange mitigates known attacks.

Related Terms

Transport Layer Security TLS 1.3 Cipher Suite Perfect Forward Secrecy SSL/TLS Handshake
Disclaimer: DomainOptic provides automated informational scans only. Results do not constitute professional security advice, compliance certification, or a guarantee of security. Always verify findings independently.