Description
In kernel/bpf/verifier.c in the Linux kernel before 5.12.13, a branch can be mispredicted (e.g., because of type confusion) and consequently an unprivileged BPF program can read arbitrary memory locations via a side-channel attack, aka CID-9183671af6db.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | linux | 5.10.46-1 | — |
| Debian 13 | linux | 5.10.46-1 | — |
| Debian 12 | linux | 5.10.46-1 | — |
| Debian 9 | linux-4.19 | 4.19.208-1~deb9u1 | DLA-2785-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 24.04 LTS | linux-raspi-realtime | No fix yet | — |
| Ubuntu 22.04 LTS | linux-realtime +1 | No fix yet | — |
| Ubuntu 20.04 LTS | linux | 5.4.0-88.99 | USN-5091-1 |
| Ubuntu 20.04 LTS | linux-aws | 5.4.0-1057.60 | USN-5091-1 |
| Ubuntu 20.04 LTS | linux-aws-5.11 +1 | 5.11.0-1019.20~20.04.1 | USN-5092-2, USN-5092-1 |
| Ubuntu 20.04 LTS | linux-azure | 5.4.0-1059.62 | USN-5091-1 |
| Ubuntu 20.04 LTS | linux-azure-5.11 | 5.11.0-1017.18~20.04.1 | USN-5092-2 |
| Ubuntu 20.04 LTS | linux-bluefield | 5.4.0-1019.22 | — |
| Ubuntu 20.04 LTS | linux-gcp | 5.4.0-1053.57 | USN-5091-1 |
| Ubuntu 20.04 LTS | linux-gcp-5.11 | 5.11.0-1020.22~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-gke | 5.4.0-1053.56 | USN-5091-1 |
| Ubuntu 20.04 LTS | linux-gkeop | 5.4.0-1024.25 | USN-5091-1 |
| Ubuntu 20.04 LTS | linux-hwe-5.11 | 5.11.0-37.41~20.04.2 | USN-5092-2 |
| Ubuntu 20.04 LTS | linux-ibm | 5.4.0-1005.6 | — |
| Ubuntu 20.04 LTS | linux-kvm | 5.4.0-1047.49 | USN-5091-1 |
| Ubuntu 20.04 LTS | linux-oem-5.10 | 5.10.0-1050.52 | USN-5115-1 |
| Ubuntu 20.04 LTS | linux-oracle | 5.4.0-1055.59 | USN-5091-1 |
| Ubuntu 20.04 LTS | linux-raspi | 5.4.0-1044.48 | USN-5091-2 |
| Ubuntu 20.04 LTS | linux-riscv +8 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-riscv-5.11 | 5.11.0-1020.21~20.04.1 | — |
| Ubuntu 18.04 LTS | linux-aws-5.4 | 5.4.0-1057.60~18.04.1 | USN-5091-1 |
| Ubuntu 18.04 LTS | linux-azure-5.4 | 5.4.0-1059.62~18.04.1 | USN-5091-1 |
| Ubuntu 18.04 LTS | linux-gcp +13 | No fix yet | — |
| Ubuntu 18.04 LTS | linux-gcp-5.4 | 5.4.0-1053.57~18.04.1 | USN-5091-1 |
| Ubuntu 18.04 LTS | linux-gke-5.4 | 5.4.0-1053.56~18.04.1 | USN-5091-1 |
| Ubuntu 18.04 LTS | linux-gkeop-5.4 | 5.4.0-1024.25~18.04.1 | USN-5091-1 |
| Ubuntu 18.04 LTS | linux-hwe-5.4 | 5.4.0-87.98~18.04.1 | USN-5091-1 |
| Ubuntu 18.04 LTS | linux-oracle-5.4 | 5.4.0-1055.59~18.04.1 | USN-5091-1 |
| Ubuntu 18.04 LTS | linux-raspi-5.4 | 5.4.0-1044.48~18.04.1 | USN-5091-2 |
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
Show 9 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro FIPS 20.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS 18.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS 16.04 LTS | linux-fips | No fix yet | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-aws-fips | 5.4.0-1069.73+fips2 | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-azure-fips | 5.4.0-1073.76+fips1 | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-fips | 5.4.0-1034.40 | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-gcp-fips | 5.4.0-1067.71~20.04.1 | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS-updates 16.04 LTS | linux-fips | No fix yet | — |
| Ubuntu Pro 18.04 LTS | linux +5 | No fix yet | — |
| Ubuntu Pro 16.04 LTS | linux +7 | No fix yet | — |
| Ubuntu Pro 14.04 LTS | linux-aws +2 | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP3 | kernel-64kb +7 | 5.3.18-59.13.1 | SUSE-SU-2021:2352-1 |
| SLES 15 SP3 | kernel-azure +2 | 5.3.18-38.11.1 | SUSE-SU-2021:2305-1 |
| SLES 15 SP3 | kernel-default-base | 5.3.18-59.13.1.18.6.1 | SUSE-SU-2021:2352-1 |
| SLES 15 SP2 | kernel-azure +2 | 5.3.18-18.53.1 | SUSE-SU-2021:2303-1 |
| SLES 15 SP2 | kernel-default-base | 5.3.18-24.70.1.9.32.1 | SUSE-SU-2021:2325-1 |
| SLES 15 SP2 | kernel-docs +5 | 5.3.18-24.70.1 | SUSE-SU-2021:2325-1 |
| SLES 15 SP1 | kernel-docs +5 | 4.12.14-197.99.1 | SUSE-SU-2021:2427-1 |
| SLES 15 | kernel-docs +6 | 4.12.14-150.75.1 | SUSE-SU-2021:2421-1 |
| SLES 12 SP5 | kernel-azure +2 | 4.12.14-16.62.1 | SUSE-SU-2021:2321-1 |
| SLES 12 SP5 | kernel-docs +4 | 4.12.14-122.77.1 | SUSE-SU-2021:2324-1 |
Show 22 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP4 | kernel-syms +2 | 4.12.14-95.80.1 | SUSE-SU-2021:2422-1 |
| SLES for SAP 15 SP1 | kernel-docs +4 | 4.12.14-197.99.1 | SUSE-SU-2021:2427-1 |
| SLES for SAP 15 | kernel-docs +5 | 4.12.14-150.75.1 | SUSE-SU-2021:2421-1 |
| SLES for SAP 12 SP5 | kernel-azure +2 | 4.12.14-16.62.1 | SUSE-SU-2021:2321-1 |
| SLES for SAP 12 SP5 | kernel-syms +2 | 4.12.14-122.77.1 | SUSE-SU-2021:2324-1 |
| SLES for SAP 12 SP4 | kernel-syms +2 | 4.12.14-95.80.1 | SUSE-SU-2021:2422-1 |
| SLE Real Time 12 SP5 | kernel-rt +3 | 4.12.14-10.49.1 | SUSE-SU-2021:2349-1 |
| SLE Micro 5.0 | kernel-default | 5.3.18-24.70.1 | SUSE-SU-2021:2325-1 |
| SLE Micro 5.0 | kernel-default-base | 5.3.18-24.70.1.9.32.1 | SUSE-SU-2021:2325-1 |
| SLE Micro 5.0 | kernel-rt | 4.12.14-10.49.1 | SUSE-SU-2021:2349-1 |
| SLE Live Patching 15 SP3 | kernel-default | 5.3.18-59.13.1 | SUSE-SU-2021:2352-1 |
| SLE Live Patching 15 SP3 | kernel-livepatch-SLE15-SP3_Update_3 | 1-7.3.1 | SUSE-SU-2021:2352-1 |
| SLE Live Patching 15 SP2 | kernel-default | 5.3.18-24.70.1 | SUSE-SU-2021:2325-1 |
| SLE Live Patching 15 SP2 | kernel-livepatch-SLE15-SP2_Update_16 | 1-5.3.1 | SUSE-SU-2021:2325-1 |
| SLE Live Patching 15 SP1 | kernel-default | 4.12.14-197.99.1 | SUSE-SU-2021:2427-1 |
| SLE Live Patching 15 SP1 | kernel-livepatch-SLE15-SP1_Update_26 | 1-3.3.3 | SUSE-SU-2021:2427-1 |
| SLE Live Patching 15 | kernel-default | 4.12.14-150.75.1 | SUSE-SU-2021:2421-1 |
| SLE Live Patching 15 | kernel-livepatch-SLE15_Update_25 | 1-1.3.1 | SUSE-SU-2021:2421-1 |
| SLE Live Patching 12 SP5 | kernel-default | 4.12.14-122.77.1 | SUSE-SU-2021:2324-1 |
| SLE Live Patching 12 SP5 | kgraft-patch-SLE12-SP5_Update_20 | 1-8.3.1 | SUSE-SU-2021:2324-1 |
| SLE Live Patching 12 SP4 | kernel-default | 4.12.14-95.80.1 | SUSE-SU-2021:2422-1 |
| SLE Live Patching 12 SP4 | kgraft-patch-SLE12-SP4_Update_22 | 1-6.3.1 | SUSE-SU-2021:2422-1 |
| SLE HPC 15 SP1 | kernel-docs +4 | 4.12.14-197.99.1 | SUSE-SU-2021:2427-1 |
| SLE HPC 15 | kernel-docs +5 | 4.12.14-150.75.1 | SUSE-SU-2021:2421-1 |
| SUSE Real Time Module 15 SP2 | kernel-rt +1 | 5.3.18-42.2 | SUSE-SU-2021:2426-1 |
| SUSE Real Time Module 15 SP2 | kernel-syms-rt +1 | 5.3.18-42.1 | SUSE-SU-2021:2426-1 |
| SUSE Real Time Module 15 SP2 | lttng-modules | 2.10.10-1.5.1 | SUSE-SU-2021:2426-1 |
| SUSE Real Time Module 15 SP2 | oracleasm | 2.0.8-1.3.1 | SUSE-SU-2021:2426-1 |
| SUSE OpenStack Cloud Crowbar 9 | kernel-syms +2 | 4.12.14-95.80.1 | SUSE-SU-2021:2422-1 |
| SUSE OpenStack Cloud 9 | kernel-syms +2 | 4.12.14-95.80.1 | SUSE-SU-2021:2422-1 |
| SUSE Manager Server 4.0 | kernel-docs +5 | 4.12.14-197.99.1 | SUSE-SU-2021:2427-1 |
| SUSE Manager Retail Branch Server 4.0 | kernel-docs +4 | 4.12.14-197.99.1 | SUSE-SU-2021:2427-1 |
| SUSE Manager Proxy 4.0 | kernel-docs +4 | 4.12.14-197.99.1 | SUSE-SU-2021:2427-1 |
| SUSE Enterprise Storage 6 | kernel-docs +4 | 4.12.14-197.99.1 | SUSE-SU-2021:2427-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 15.3 | kernel-64kb +6 | 5.3.18-59.13.1 | openSUSE-SU-2021:2352-1 |
| openSUSE Leap 15.3 | kernel-azure +2 | 5.3.18-38.11.1 | openSUSE-SU-2021:2305-1 |
| openSUSE Leap 15.3 | kernel-debug +4 | 4.12.14-197.99.1 | openSUSE-SU-2021:2427-1, openSUSE-SU-2021:2352-1 |
| openSUSE Leap 15.3 | kernel-default-base | 5.3.18-59.13.1.18.6.1 | openSUSE-SU-2021:2352-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | kernel-livepatch-4.14.238-182.421 | 1.0-0.amzn2 | ALAS2-2021-1685 |
| Amazon Linux 2 | perf +8 | 4.14.238-182.421.amzn2 | ALAS2-2021-1685 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 2 (CBL-Mariner) | kernel | 5.10.78.1-1 | — |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.
GitHub 1 repository
-
benschlueter/CVE-2021-33624 ★ 4 · Jun 25, 2021
Proof of Concept for CVE-2021-33624
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 22
- USN-5115-1 linux-oem-5.10 vulnerabilities Ubuntu Security Notices (USN) · Sep 14, 2026
- USN-5092-1 linux, linux-aws, linux-aws-5.11, linux-gcp, linux-kvm, linux-oracle, linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Jun 3, 2026
- USN-5092-2 linux-hwe-5.11, linux-azure, linux-azure-5.11, linux-oracle-5.11 vulnerabilities Ubuntu Security Notices (USN) · Jun 3, 2026
- USN-5091-1 linux, linux-aws, linux-aws-5.4, linux-azure, linux-azure-5.4, linux-gcp, linux-gcp-5.4, linux-gke, linux-gke-5.4, linux-gkeop, linux-gkeop-5.4, linux-hwe-5.4, linux-kvm, linux-oracle, linux-oracle-5.4 vulnerabilities Ubuntu Security Notices (USN) · Jun 3, 2026
- USN-5091-2 linux-raspi, linux-raspi-5.4 vulnerabilities Ubuntu Security Notices (USN) · Jun 3, 2026
- DLA-2785-1 linux-4.19 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2021:2426-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:2422-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:2325-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:2305-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:2421-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:2349-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:2352-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:2321-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:2305-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:2324-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:2303-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:2427-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:2427-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:2352-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- ALAS2-2021-1685 Important: kernel security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Oct 2, 2025
- WID-SEC-2022-0112 Google Android: Mehrere Schwachstellen ermöglichen Privilegieneskalation BSI CERT-Bund (WID) · Jul 3, 2024
References
- https://www.usenix.org/conference/usenixsecurity21/presentation/kirzner
- http://www.openwall.com/lists/oss-security/2021/06/21/1
- https://github.com/torvalds/linux/commit/9183671af6dbf60a1219371d4ed73e23f43b49db
- [debian-lts-announce] 20211015 [SECURITY] [DLA 2785-1] linux-4.19 security update mailing-list
- https://github.com/benschlueter/CVE-2021-33624