Description
OpenBSD kernel version <= 6.5 can be forced to create long chains of TCP SACK holes that causes very expensive calls to tcp_sack_option() for every incoming SACK packet which can lead to a denial of service.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| — | OpenBSD | All, including latest - 6.5 | — |
Advisories 3
- SSA-462066 SSA-462066: Vulnerability known as TCP SACK PANIC in Industrial Products Siemens ProductCERT · Apr 11, 2023
- WID-SEC-2023-0914 OpenBSD: Schwachstelle ermöglicht Denial of Service BSI CERT-Bund (WID) · Apr 10, 2023
- ICSA-19-253-03 ICSA-19-253-03_Siemens Industrial Products (Update P) CISA ICS & IT advisories · May 12, 2022
References
- https://github.com/openbsd/src/commit/ed8fdce754a5d8d14c09e989d8877707bd43906f
- https://ftp.openbsd.org/pub/OpenBSD/patches/6.5/common/006_tcpsack.patch.sig
- https://security.netapp.com/advisory/ntap-20190905-0001/
- https://research.checkpoint.com/tcp-sack-security-issue-in-openbsd-cve-2019-8460/
- https://us-cert.cisa.gov/ics/advisories/icsa-19-253-03