CVE-2020-1763 Denial of service in libreswan
An unauthenticated attacker can crash the libreswan pluto daemon by sending specially crafted IKEv1 packets, causing a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2020-1763?
CVE-2020-1763 is a high-severity denial of service vulnerability in the libreswan Project libreswan, published on 12 May 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
An out-of-bounds buffer read flaw was found in the pluto daemon of libreswan from versions 3.27 till 3.31 where, an unauthenticated attacker could use this flaw to crash libreswan by sending specially-crafted IKEv1 Informational Exchange packets. The daemon respawns after the crash.
Weakness: CWE-125
Which versions are affected by CVE-2020-1763?
It affects 1 product.
Linux distribution packages (9)
libreswan Red Hat:enterprise_linux:8::appstream | All versions | 0:3.29-7.el8_2 |
libreswan-debuginfo Red Hat:enterprise_linux:8::appstream | All versions | 0:3.29-7.el8_2 |
libreswan-debugsource Red Hat:enterprise_linux:8::appstream | All versions | 0:3.29-7.el8_2 |
libreswan Red Hat:rhel_e4s:8.0::appstream | All versions | 0:3.27-10.el8_0 |
libreswan-debuginfo Red Hat:rhel_e4s:8.0::appstream | All versions | 0:3.27-10.el8_0 |
libreswan-debugsource Red Hat:rhel_e4s:8.0::appstream | All versions | 0:3.27-10.el8_0 |
libreswan Red Hat:rhel_eus:8.1::appstream | All versions | 0:3.29-7.el8_1 |
libreswan-debuginfo Red Hat:rhel_eus:8.1::appstream | All versions | 0:3.29-7.el8_1 |
libreswan-debugsource Red Hat:rhel_eus:8.1::appstream | All versions | 0:3.29-7.el8_1 |
Products include Libreswan Libreswan.
How do I fix CVE-2020-1763?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2020-1763 being exploited?
There is no known exploitation of CVE-2020-1763 in the wild and no public exploit code.
Other vulnerabilities in the libreswan Project libreswan
- CVE-2013-7283 Race condition in n/a
- CVE-2026-12413 IKEv2 Denial of Service via malformed fragmentation
- CVE-2026-50721 IKEv1 Denial of Service via RSA-SHA1 (PKCS#1 Version 1.5 Encrypted) authentication payload
- CVE-2026-50722 IKEv2 Denial of Service via RSA-SHA1 (PKCS#1 RSASSA-PKCS1-v1_5) authentication payload
- CVE-2023-30570 Denial of service in n/a
Sources
Also known as DEBIAN-CVE-2020-1763, DSA-4684-1, GHSA-wx69-vm3h-3cgv, MGASA-2020-0215, RHSA-2020:2069, RHSA-2020:2070 and 2 more.