CVE-2021-33033
HIGH
7.8
CVSS Score
Published: May 14, 2021 at 10:57 PM UTC
Updated: August 5, 2026 at 06:54 PM UTC
1 product affected across 1 vendorLinux Kernel
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Severity
HIGH7.8
Exploit prediction
EPSS 0.6%
Description
The Linux kernel before 5.11.14 has a use-after-free in cipso_v4_genopt in net/ipv4/cipso_ipv4.c because the CIPSO and CALIPSO refcounting for the DOI definitions is mishandled, aka CID-ad5d07f4a9cd. This leads to writing an arbitrary value.
Affected
Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.
2.6.28 ≤ v < 4.9.2984.10 ≤ v < 4.14.2264.15 ≤ v < 4.19.1814.20 ≤ v < 5.4.1065.11 ≤ v < 5.11.75.5 ≤ v < 5.10.24
Affected range stops below 4.14.226, so it looks safe — our inference, not a vendor statement
Affected range stops below 4.19.181, so it looks safe — our inference, not a vendor statement
Affected range stops below 4.9.298, so it looks safe — our inference, not a vendor statement
Affected range stops below 5.10.24, so it looks safe — our inference, not a vendor statement
Affected range stops below 5.11.7, so it looks safe — our inference, not a vendor statement
Affected range stops below 5.4.106, 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-5.11.14
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.7
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1165affd484889d4986cf3b724318935a0b120d8
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ad5d07f4a9cd671233ae20983848874731102c08
References (6)
x_refsource_MISCMailing ListPatchVendor Advisory
Source: [email protected]
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.14x_refsource_MISCMailing ListPatchVendor Advisory
Source: [email protected]
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.7x_refsource_MISCMailing ListPatchVendor Advisory
Source: [email protected]
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1165affd484889d4986cf3b724318935a0b120d8x_refsource_MISCMailing ListPatchVendor Advisory
Source: [email protected]
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ad5d07f4a9cd671233ae20983848874731102c08x_refsource_MISCExploitThird Party Advisory
Source: [email protected]
https://sites.google.com/view/syzscope/kasan-use-after-free-read-in-cipso_v4_genoptx_refsource_MISCExploitMailing ListThird Party Advisory
Source: [email protected]
https://syzkaller.appspot.com/bug?id=96e7d345748d8814901c91cd92084ed04b46701eCVSS
- 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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