CVE-2019-8460

moderate-risk
Published 2019-08-26

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.

Do I need to act?

-
0.69% chance of exploitation
EPSS score — low exploit probability
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Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
7
CVSS 7.5/10 High
NETWORK / LOW complexity

Affected Products (1)

Affected Vendors

Openbsd

References (10)

Exploit https://ftp.openbsd.org/pub/OpenBSD/patches/6.5/common/006_tcpsack.patch.sig
Patch https://github.com/openbsd/src/commit/ed8fdce754a5d8d14c09e989d8877707bd43906f
Exploit https://research.checkpoint.com/tcp-sack-security-issue-in-openbsd-cve-2019-8460...
Third Party Advisory https://security.netapp.com/advisory/ntap-20190905-0001/
https://us-cert.cisa.gov/ics/advisories/icsa-19-253-03
Exploit https://ftp.openbsd.org/pub/OpenBSD/patches/6.5/common/006_tcpsack.patch.sig
Patch https://github.com/openbsd/src/commit/ed8fdce754a5d8d14c09e989d8877707bd43906f
Exploit https://research.checkpoint.com/tcp-sack-security-issue-in-openbsd-cve-2019-8460...
Third Party Advisory https://security.netapp.com/advisory/ntap-20190905-0001/
https://us-cert.cisa.gov/ics/advisories/icsa-19-253-03
33
/ 100
moderate-risk
Severity 26/34 · High
Exploitability 2/34 · Minimal
Exposure 5/34 · Minimal