CVE-2019-6593 — On BIG-IP 11

On BIG-IP 11.5.1-11.5.4, 11.6.1, and 12.1.0, a virtual server configured with a Client SSL profile may be vulnerable to a chosen ciphertext attack against CBC ciphers. When exploited, this may result in plaintext recovery of encrypted messages through a man-in-the-middle (MITM) a

01What is this vulnerability?

On BIG-IP 11.5.1-11.5.4, 11.6.1, and 12.1.0, a virtual server configured with a Client SSL profile may be vulnerable to a chosen ciphertext attack against CBC ciphers. When exploited, this may result in plaintext recovery of encrypted messages through a man-in-the-middle (MITM) attack, despite the attacker not having gained access to the server's private key itself. (CVE-2019-6593 also known as…

02Affected products

Vendor	Product	Versions
F5 Networks, Inc.	BIG	IP (LTM, AAM, AFM, Analytics, APM, ASM, DNS, Edge Gateway, FPS, GTM, Link Controller, PEM, WebAccelerator) — 11.5.1-11.5.4, 11.6.1, 12.1.0

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2019-02-26T15:00:00.000Z
• Last modified: 2024-09-16T19:01:08.562Z

09References

• support.f5.com — https://support.f5.com/csp/article/K10065173