When dealing with legacy systems like RHEL4 running Apache 2.0, security patching becomes particularly challenging. The BEAST (Browser Exploit Against SSL/TLS) vulnerability specifically targets CBC-mode ciphers in SSLv3 and TLSv1.0. While modern systems would simply upgrade to TLS 1.1+ or Apache 2.2+, our hands are tied by:

• Ancient package dependencies that prevent Apache upgrades
• Impending server retirement making OS upgrades impractical
• PCI compliance requirements demanding immediate mitigation

Unlike Apache 2.2+, version 2.0 lacks critical SSL directives like SSLHonorCipherOrder. Our testing confirmed these limitations:

# This WON'T work in Apache 2.0:
SSLProtocol -ALL +SSLv3 +TLSv1
SSLHonorCipherOrder On  # Unrecognized directive
SSLCipherSuite RC4-SHA:HIGH:!ADH

Through extensive testing, we developed these effective approaches:

Method 1: Force RC4 Cipher Suite (Primary Solution)

# In httpd.conf or ssl.conf:
SSLCipherSuite RC4-SHA:HIGH:!ADH:!aNULL:!MD5

# Verify with:
openssl s_client -connect yourdomain:443 -ssl3
openssl s_client -connect yourdomain:443 -tls1

Why this works: RC4 isn't vulnerable to BEAST as it's a stream cipher. While RC4 has its own vulnerabilities, it's the lesser evil for legacy systems.

Method 2: Disable All CBC Ciphers Manually

SSLCipherSuite !AES256-SHA:!AES128-SHA:!DES-CBC3-SHA:!DES-CBC-SHA:!EDH-RSA-DES-CBC-SHA:!EDH-DSS-DES-CBC-SHA

Note: This may break compatibility with some clients as it removes all CBC-mode ciphers.

Method 3: Partial Mitigation via SSLProtocol

# At least disable SSLv2 (though BEAST affects SSLv3+)
SSLProtocol ALL -SSLv2

After implementation, verify using these tools:

1. OpenSSL command-line tests:

   openssl s_client -connect localhost:443 -cipher RC4-SHA
   

2. Online scanners like SSL Labs' SSL Test
3. PCI ASV rescan

While these workarounds address BEAST, remember:

• RC4 is deprecated in modern standards (RFC 7465)
• TLS 1.0 is obsolete (PCI DSS 3.2 requires disabling by June 2018)
• These are temporary fixes until server retirement

If cipher limitations prove too restrictive, consider:

# stunnel.conf example:
[apache]
accept = 443
connect = 8080
cert = /etc/stunnel/stunnel.pem
sslVersion = TLSv1
options = NO_SSLv2
ciphers = RC4-SHA

This creates a TLS proxy while keeping Apache on plain HTTP.

---

The BEAST (Browser Exploit Against SSL/TLS) vulnerability affects servers using SSLv3.0 or TLSv1.0 with CBC (Cipher Block Chaining) mode ciphers. This cryptographic weakness, discovered in 2011 but rooted in a 2004 protocol design flaw, allows potential attackers to decrypt parts of encrypted sessions.

Modern solutions like SSLHonorCipherOrder and TLS 1.1+ upgrades don't work on Apache 2.0. The configuration directive:

SSLHonorCipherOrder On
SSLCipherSuite RC4-SHA:HIGH:!ADH

only became available in Apache 2.2. For legacy systems like RHEL 4 running Apache 2.0, we need alternative approaches.

While Apache 2.0 lacks SSLHonorCipherOrder, we can manually specify non-CBC ciphers:

SSLCipherSuite ALL:!ADH:!EXP:!SSLv2:!LOW:!MEDIUM:!CBC

This explicitly excludes all CBC-mode ciphers while allowing RC4 and other non-CBC alternatives. Verify with:

openssl ciphers -v 'ALL:!ADH:!EXP:!SSLv2:!LOW:!MEDIUM:!CBC'

For maximum compatibility with older clients while avoiding CBC:

SSLCipherSuite RC4-SHA

Note that RC4 has its own vulnerabilities (later discovered), but was considered acceptable for PCI compliance when BEAST was the primary concern.

After making changes, test with:

openssl s_client -connect yourserver:443 -ssl3

And verify no CBC ciphers appear in the negotiated cipher list. For automated testing:

nmap --script ssl-enum-ciphers -p 443 yourserver

1. These workarounds may break compatibility with some older browsers
2. The server remains vulnerable to other SSL/TLS issues like POODLE
3. This is strictly a short-term solution until retirement
4. Consider adding SSLProtocol -ALL +SSLv3 +TLSv1 to disable SSLv2