CVE-2021-3449 NULL pointer deref in signature_algorithms processing
A remote attacker can crash an OpenSSL TLS server by sending a crafted renegotiation ClientHello message, 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-2021-3449?
CVE-2021-3449 is a medium-severity vulnerability in Debian Debian Linux, published on 25 Mar 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
An OpenSSL TLS server may crash if sent a maliciously crafted renegotiation ClientHello message from a client. If a TLSv1.2 renegotiation ClientHello omits the signature_algorithms extension (where it was present in the initial ClientHello), but includes a signature_algorithms_cert extension then a NULL pointer dereference will result, leading to a crash and a denial of service attack. A server is only vulnerable if it has TLSv1.2 and renegotiation enabled (which is the default configuration). OpenSSL TLS clients are not impacted by this issue. All OpenSSL 1.1.1 versions are affected by this issue. Users of these versions should upgrade to OpenSSL 1.1.1k. OpenSSL 1.0.2 is not impacted by this issue. Fixed in OpenSSL 1.1.1k (Affected 1.1.1-1.1.1j).
Weakness: CWE-476
Which versions are affected by CVE-2021-3449?
5 open source packages ship an affected version, including openssl-src, node and node-min. It affects 106 products.
| Package | Affected | Fixed in |
|---|---|---|
openssl-src crates.io | All versions | 111.15.0 |
openssl-src crates.io | All versions | 111.15.0 |
openssl-src crates.io | From 0.0.0-0 | 111.15.0 |
node Bitnami | From 10.0.0 | 10.12.1, 10.24.1, 12.12.1, 12.22.1, 14.14.1, 14.16.1, 15.14.0 |
node-min Bitnami | From 10.0.0 | 10.12.1, 10.24.1, 12.12.1, 12.22.1, 14.14.1, 14.16.1, 15.14.0 |
Linux distribution packages (25)
openssl Red Hat:rhel_eus:8.1::baseos | All versions | 1:1.1.1c-5.el8_1 |
openssl-debuginfo Red Hat:rhel_eus:8.1::baseos | All versions | 1:1.1.1c-5.el8_1 |
openssl-debugsource Red Hat:rhel_eus:8.1::baseos | All versions | 1:1.1.1c-5.el8_1 |
openssl-devel Red Hat:rhel_eus:8.1::baseos | All versions | 1:1.1.1c-5.el8_1 |
openssl-libs Red Hat:rhel_eus:8.1::baseos | All versions | 1:1.1.1c-5.el8_1 |
openssl-libs-debuginfo Red Hat:rhel_eus:8.1::baseos | All versions | 1:1.1.1c-5.el8_1 |
openssl-perl Red Hat:rhel_eus:8.1::baseos | All versions | 1:1.1.1c-5.el8_1 |
openssl Red Hat:rhel_eus:8.2::baseos | All versions | 1:1.1.1c-18.el8_2 |
openssl-debuginfo Red Hat:rhel_eus:8.2::baseos | All versions | 1:1.1.1c-18.el8_2 |
openssl-debugsource Red Hat:rhel_eus:8.2::baseos | All versions | 1:1.1.1c-18.el8_2 |
openssl-devel Red Hat:rhel_eus:8.2::baseos | All versions | 1:1.1.1c-18.el8_2 |
openssl-libs Red Hat:rhel_eus:8.2::baseos | All versions | 1:1.1.1c-18.el8_2 |
openssl-libs-debuginfo Red Hat:rhel_eus:8.2::baseos | All versions | 1:1.1.1c-18.el8_2 |
openssl-perl Red Hat:rhel_eus:8.2::baseos | All versions | 1:1.1.1c-18.el8_2 |
openssl-1_1 SUSE:Linux Enterprise Micro 5.0 | All versions | 1.1.1d-11.20.1 |
openssl-1_1 SUSE:Linux Enterprise Module for Basesystem 15 SP2 | All versions | 1.1.1d-11.20.1 |
openssl-1_1 SUSE:Linux Enterprise Module for Certifications 15 SP3 | All versions | 1.1.1d-11.20.1 |
openssl-1_1 SUSE:Linux Enterprise Server 12 SP4-LTSS | All versions | 1.1.1d-2.33.1 |
openssl-1_1 SUSE:Linux Enterprise Server 12 SP5 | All versions | 1.1.1d-2.33.1 |
openssl-1_1 SUSE:Linux Enterprise Server for SAP Applications 12 SP4 | All versions | 1.1.1d-2.33.1 |
openssl-1_1 SUSE:Linux Enterprise Server for SAP Applications 12 SP5 | All versions | 1.1.1d-2.33.1 |
openssl-1_1 SUSE:Linux Enterprise Software Development Kit 12 SP5 | All versions | 1.1.1d-2.33.1 |
openssl-1_1 SUSE:OpenStack Cloud 9 | All versions | 1.1.1d-2.33.1 |
openssl-1_1 SUSE:OpenStack Cloud Crowbar 9 | All versions | 1.1.1d-2.33.1 |
openssl-1_1 openSUSE:Leap 15.2 | All versions | 1.1.1d-lp152.7.15.1 |
Products include Checkpoint Multi-Domain Management Firmware, Checkpoint Quantum Security Gateway Firmware, Checkpoint Quantum Security Management Firmware, Debian Debian Linux, Fedoraproject Fedora, Freebsd Freebsd and 100 more.
How do I fix CVE-2021-3449?
Upgrade openssl-src to 111.15.0 or later.
Is CVE-2021-3449 being exploited?
There is no known exploitation of CVE-2021-3449 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Sources
Also known as ALPINE-CVE-2021-3449, BIT-node-2021-3449, BIT-node-min-2021-3449, CLEANSTART-2026-RT76618, DEBIAN-CVE-2021-3449, DSA-4875-1 and 12 more.