Vulnerability in F5 Big-Ip Access Policy Manager
CVE-2019-1559
If an application encounters a fatal protocol error and then calls SSL_shutdown() twice (once to send a close_notify, and once to receive one) then OpenSSL can respond differently to the calling application if a 0 byte record is received with invalid padding compared to if a 0 byte record is received with an invalid MAC. If the application then behaves differently based on that in a way that is detectable to the remote peer, then this amounts to a padding oracle that could be used to decrypt data. In order for this to be exploitable "non-stitched" ciphersuites must be in use. Stitched ciphersuites are optimised implementations of certain commonly used ciphersuites. Also the application must call SSL_shutdown() twice even if a protocol error has occurred (applications should not do this but some do anyway). Fixed in OpenSSL 1.0.2r (Affected 1.0.2-1.0.2q).
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.171 (97.1th percentile), scored .
Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 97th percentile — 97.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.171 · newest: 0.171 · change: 0.000
Affected products
- F5 Big-Ip Access Policy Manager
- F5 Big-Ip Advanced Firewall Manager
- F5 Big-Ip Analytics
- F5 Big-Ip Application Acceleration Manager
- F5 Big-Ip Application Security Manager
- F5 Big-Ip Domain Name System
- F5 Big-Ip Edge Gateway
- F5 Big-Ip Fraud Protection Service
- F5 Big-Ip Global Traffic Manager
- F5 Big-Ip Link Controller
Weakness classification (CWE)
Public proof-of-concept exploits
References
- www.securityfocus.com/bid/107174 (VDB Entry, Third Party Advisory, vdb-entry)
- security.gentoo.org/glsa/201903-10 (vendor-advisory, Third Party Advisory)
- usn.ubuntu.com/3899-1/ (vendor-advisory, Third Party Advisory)
- lists.debian.org/debian-lts-announce/2019/03/msg00003.html (mailing-list, Mailing List, Third Party Advisory)
- www.debian.org/security/2019/dsa-4400 (vendor-advisory, Third Party Advisory)
- lists.opensuse.org/opensuse-security-announce/2019-03/msg00041.html (vendor-advisory, Mailing List, Third Party Advisory)
- lists.opensuse.org/opensuse-security-announce/2019-04/msg00019.html (vendor-advisory, Mailing List, Third Party Advisory)
- lists.opensuse.org/opensuse-security-announce/2019-04/msg00046.html (vendor-advisory, Mailing List, Third Party Advisory)
- lists.opensuse.org/opensuse-security-announce/2019-04/msg00047.html (vendor-advisory, Mailing List, Third Party Advisory)
- lists.opensuse.org/opensuse-security-announce/2019-05/msg00049.html (vendor-advisory, Mailing List, Third Party Advisory)
Frequently asked questions
- What is CVE-2019-1559?
- CVE-2019-1559 is a medium-severity vulnerability in F5 Big-Ip Access Policy Manager, classified under Observable Discrepancy. CVSS score: 5.9/10. Published 2019-02-27.
- How severe is CVE-2019-1559?
- Medium severity. CVSS v3 base score is 5.9 out of 10.
- Is CVE-2019-1559 known to be exploited?
- 6 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.