CVE-2021-33034
HIGH
7.8
CVSS Score
Published: May 14, 2021 at 10:57 PM UTC
Updated: August 13, 2026 at 07:47 PM UTC
3 products affected across 3 vendorsLinux KernelDebian LinuxFedora
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Severity
HIGH7.8
Exploit prediction
EPSS 0.8%
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.
Affected
Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.
Debian Linux· Debiandrupal
95%95%
v < 4.4.2694.10 ≤ v < 4.14.2334.15 ≤ v < 4.19.1914.20 ≤ v < 5.4.1194.5 ≤ v < 4.9.2695.11 ≤ v < 5.11.215.12 ≤ v < 5.12.45.5 ≤ v < 5.10.37
Affected range stops below 4.14.233, so it looks safe — our inference, not a vendor statement
Affected range stops below 4.19.191, so it looks safe — our inference, not a vendor statement
Affected range stops below 4.4.269, so it looks safe — our inference, not a vendor statement
Affected range stops below 4.9.269, so it looks safe — our inference, not a vendor statement
Affected range stops below 5.10.37, so it looks safe — our inference, not a vendor statement
Affected range stops below 5.11.21, so it looks safe — our inference, not a vendor statement
Affected range stops below 5.12.4, so it looks safe — our inference, not a vendor statement
Affected range stops below 5.4.119, so it looks safe — our inference, not a vendor statement
Remediation
No guide yetNo remediation guidance has been written for this CVE yet. What the record does show:
Patch and advisory references
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.12.4
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5c4c8c9544099bb9043a10a5318130a943e32fc3
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GI7Z7UBWBGD3ABNIL2DC7RQDCGA4UVQW/
References (7)
x_refsource_MISCMailing ListPatchVendor Advisory
Source: [email protected]
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.12.4x_refsource_MISCMailing ListPatchVendor Advisory
Source: [email protected]
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5c4c8c9544099bb9043a10a5318130a943e32fc3Mailing Listx_refsource_MLISTThird Party Advisory
Source: [email protected]
https://lists.debian.org/debian-lts-announce/2021/06/msg00019.htmlMailing Listx_refsource_MLISTThird Party Advisory
Source: [email protected]
https://lists.debian.org/debian-lts-announce/2021/06/msg00020.htmlVendor Advisoryx_refsource_FEDORABroken Link
Source: [email protected]
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GI7Z7UBWBGD3ABNIL2DC7RQDCGA4UVQW/x_refsource_MISCExploitThird Party Advisory
Source: [email protected]
https://sites.google.com/view/syzscope/kasan-use-after-free-read-in-hci_send_aclx_refsource_MISCExploitMailing ListThird Party Advisory
Source: [email protected]
https://syzkaller.appspot.com/bug?id=2e1943a94647f7732dd6fc60368642d6e8dc91b1CVSS
- Attack Vector
- LOCAL
- Complexity
- LOW
- Privileges
- LOW
- User Interaction
- NONE
- Scope
- UNCHANGED
- Confidentiality
- HIGH
- Integrity
- HIGH
- Availability
- HIGH
Vector?
Quick Info
StatusANALYZED
CWE
CWE-416
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