CVE-2021-33034
In the Linux kernel before 5.12.4, net/bluetooth/hci_event.c has a use-after-free when destroying an hci_chan, aka CID-5c4c8c954409. This leads to writing an arbitrary value.
02 Description
In the Linux kernel before 5.12.4, net/bluetooth/hci_event.c has a use-after-free when destroying an hci_chan, aka CID-5c4c8c954409. This leads to writing an arbitrary value.
03 Exploitation and scoring
- Exploitation
- Not assessed. CISA has not published an exploitation assessment for this record, and it is not in the KEV catalog. That is an absence of assessment, not a finding of no risk.
- SSVC decision
- Not assessed by CISA
- EPSS probability
- 0.82% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 57.1% of scored records. A rank, not a probability.
- NVD base score
- 7.8 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- NVD analysis status
- Analyzed. NVD last modified this record on 2026-08-13.
- Red Hat severity
- Important. Red Hat's rating for its own products, not a CVSS rating.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2021-05-14 22:57Z5 YR AGO
- Last updated
- 2024-08-03 23:42Z2 YR AGO
- Reserved
- 2021-05-14
- Assigning CNA
- mitre
- Record state
- PUBLISHED
- Severity
- Not rated by the issuing CNA
- CNA CVSS vector
- Not published by the issuing CNA
- Weaknesses
- CWE-416Use After FreeVariant
- Data version
- 5.1
- Document digest
- 97fdcf8e56bbf768d4f02602cf36fa8a884cb9c17d8643a05ac4a00776a52b91
05 Affected products
06 References
- syzkaller.appspot.comhttps://syzkaller.appspot.com/bug?id=2e1943a94647f7732dd6fc60368642d6e8dc91b1
- sites.google.comhttps://sites.google.com/view/syzscope/kasan-use-after-free-read-in-hci_send_acl
- git.kernel.orghttps://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5c4c8c9544099bb9043a10a5318130a943e32fc3
- cdn.kernel.orghttps://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.12.4
- lists.fedoraproject.orgFEDORA-2021-bae582b42chttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GI7Z7UBWBGD3ABNIL2DC7RQDCGA4UVQW/
- lists.debian.org[debian-lts-announce] 20210623 [SECURITY] [DLA 2689-1] linux security updatehttps://lists.debian.org/debian-lts-announce/2021/06/msg00020.html
- lists.debian.org[debian-lts-announce] 20210623 [SECURITY] [DLA 2690-1] linux-4.19 security updatehttps://lists.debian.org/debian-lts-announce/2021/06/msg00019.html
07 Fixed in
AlmaLinux 8
- kernel-tools-libs-devel Fixed in 4.18.0-305.7.1.el8_4
Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
Arch Linux
- linux Fixed in 5.12.4.arch1-1
- linux-hardened Fixed in 5.11.21.hardened1-1
- linux-lts Fixed in 5.10.37-1
- linux-zen Fixed in 5.12.4.zen1-1
Source: Arch Linux Security Tracker, the Arch Linux security team. Reformatted by exploit.cc.
CloudLinux 8
- kernel-tools-libs-devel Fixed in 4.18.0-305.7.1.el8_4
Derived from AlmaLinux 8. Partial coverage: only packages taken from AlmaLinux 8 are listed.
Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
Debian 12
- linux Fixed in 5.10.38-1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 13
- linux Fixed in 5.10.38-1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 14
- linux Fixed in 5.10.38-1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 16.04 LTS
- linux-hwe-edge No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 18.04 LTS
- linux Fixed in 4.15.0-151.157
- linux-aws Fixed in 4.15.0-1109.116
- linux-aws-5.0 No fix yet
- linux-aws-5.3 No fix yet
- linux-aws-5.4 Fixed in 5.4.0-1051.53~18.04.1
- linux-azure No fix yet
- linux-azure-4.15 Fixed in 4.15.0-1121.134
- linux-azure-5.3 No fix yet
- linux-azure-5.4 Fixed in 5.4.0-1051.53~18.04.1
- linux-azure-edge No fix yet
- linux-dell300x Fixed in 4.15.0-1027.32
- linux-gcp No fix yet
- linux-gcp-4.15 Fixed in 4.15.0-1106.120
- linux-gcp-5.3 No fix yet
- linux-gcp-5.4 Fixed in 5.4.0-1046.49~18.04.1
- linux-gcp-edge No fix yet
- linux-gke-4.15 No fix yet
- linux-gke-5.4 Fixed in 5.4.0-1046.48~18.04.1
- linux-gkeop-5.4 Fixed in 5.4.0-1018.19~18.04.1
- linux-hwe No fix yet
- linux-hwe-5.4 Fixed in 5.4.0-77.86~18.04.1
- linux-hwe-edge No fix yet
- linux-kvm Fixed in 4.15.0-1097.99
- linux-oem No fix yet
- linux-oracle Fixed in 4.15.0-1078.86
- linux-oracle-5.0 No fix yet
- linux-oracle-5.3 No fix yet
- linux-oracle-5.4 Fixed in 5.4.0-1048.52~18.04.1
- linux-raspi-5.4 Fixed in 5.4.0-1038.41~18.04.1
- linux-raspi2 Fixed in 4.15.0-1092.98
- linux-snapdragon Fixed in 4.15.0-1109.118
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 20.04 LTS
- linux Fixed in 5.4.0-77.86
- linux-aws Fixed in 5.4.0-1051.53
- linux-aws-5.8 Fixed in 5.8.0-1041.43~20.04.1
- linux-azure Fixed in 5.4.0-1051.53
- linux-azure-5.8 Fixed in 5.8.0-1039.42~20.04.1
- linux-bluefield Fixed in 5.4.0-1013.16
- linux-gcp Fixed in 5.4.0-1046.49
- linux-gcp-5.8 Fixed in 5.8.0-1038.40~20.04.1
- linux-gke Fixed in 5.4.0-1046.48
- linux-gkeop Fixed in 5.4.0-1018.19
- linux-hwe-5.8 Fixed in 5.8.0-63.71~20.04.1
- linux-kvm Fixed in 5.4.0-1041.42
- linux-oem-5.10 Fixed in 5.10.0-1032.33
- linux-oem-5.6 No fix yet
- linux-oracle Fixed in 5.4.0-1048.52
- linux-oracle-5.8 Fixed in 5.8.0-1037.38~20.04.1
- linux-raspi Fixed in 5.4.0-1038.41
- linux-raspi2 No fix yet
- linux-riscv No fix yet
- linux-riscv-5.8 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 22.04 LTS
- linux-intel-iot-realtime No fix yet
- linux-realtime No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 24.04 LTS
- linux-raspi-realtime No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 14.04 LTS
- linux No fix yet
- linux-aws Fixed in 4.4.0-1099.104Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
- linux-azure Fixed in 4.15.0-1121.134~14.04.1Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
- linux-lts-xenial Fixed in 4.4.0-219.252~14.04.1Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 16.04 LTS
- linux Fixed in 4.4.0-219.252Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
- linux-aws Fixed in 4.4.0-1135.149Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
- linux-aws-hwe Fixed in 4.15.0-1109.116~16.04.1Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
- linux-azure Fixed in 4.15.0-1121.134~16.04.1Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
- linux-gcp Fixed in 4.15.0-1106.120~16.04.1Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
- linux-hwe Fixed in 4.15.0-151.157~16.04.1Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
- linux-kvm Fixed in 4.4.0-1100.109Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
- linux-oracle Fixed in 4.15.0-1078.86~16.04.1Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 20.04 LTS
- linux-azure-fde-5.15 Fixed in 5.15.0-1114.123~20.04.1Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro FIPS-updates 16.04 LTS
- linux-fips Fixed in 4.4.0-1069.75Available with Ubuntu Pro: https://ubuntu.com/pro
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro FIPS-updates 18.04 LTS
- linux-aws-fips Fixed in 4.15.0-2051.53Available with Ubuntu Pro: https://ubuntu.com/pro
- linux-azure-fips Fixed in 4.15.0-2033.37Available with Ubuntu Pro: https://ubuntu.com/pro
- linux-fips Fixed in 4.15.0-1066.75Available with Ubuntu Pro: https://ubuntu.com/pro
- linux-gcp-fips Fixed in 4.15.0-2016.18Available with Ubuntu Pro: https://ubuntu.com/pro
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro FIPS-updates 20.04 LTS
- linux-aws-fips Fixed in 5.4.0-1069.73+fips2Available with Ubuntu Pro: https://ubuntu.com/pro
- linux-azure-fips Fixed in 5.4.0-1073.76+fips1Available with Ubuntu Pro: https://ubuntu.com/pro
- linux-fips Fixed in 5.4.0-1028.32Available with Ubuntu Pro: https://ubuntu.com/pro
- linux-gcp-fips Fixed in 5.4.0-1067.71~20.04.1Available with Ubuntu Pro: https://ubuntu.com/pro
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro FIPS 16.04 LTS
- linux-fips No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro FIPS 18.04 LTS
- linux-aws-fips No fix yet
- linux-azure-fips No fix yet
- linux-fips No fix yet
- linux-gcp-fips No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro FIPS 20.04 LTS
- linux-aws-fips No fix yet
- linux-azure-fips No fix yet
- linux-fips No fix yet
- linux-gcp-fips No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.