CVE-2021-3543: fedoraproject fedora Use After Free
CVSS: 7.2v2.0HighModified
AliasesUBUNTU-CVE-2021-3543DEBIAN-CVE-2021-3543
Published 01-06-2021Last modified 03-08-2024
Vulnerability summary
CVE-2021-3543 is a high (CVSS 7.2) Use After Free vulnerability in fedoraproject fedora. EPSS estimates a 0.30% chance of exploitation in the next 30 days, higher than 21.4% of scored vulnerabilities.
CVSS score
7.2/10
010
High · v2.0 (NVD)EPSS score
0.30%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 3 · Related 1Timeline
- 01-06-2021PublishedVulnerability first disclosed.
- 03-08-2024Last modifiedVulnerability information updated.
Description
A flaw null pointer dereference in the Nitro Enclaves kernel driver was found in the way that Enclaves VMs forces closures on the enclave file descriptor. A local user of a host machine could use this flaw to crash the system or escalate their privileges on the system.
CVSS metrics
4 scores · 3 sources · 2 versionsMedium 6.7Preferred score · OSV · Ubuntu (Ecosystem advisory) · calculated from vector
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:HSourcesAll 3 agree
- OSV · DebianEcosystem advisory · calculated6.7MediumCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
- NVDNIST6.7MediumCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
High 7.2Preferred score · NVD (NIST)
AV:L/AC:L/Au:N/C:C/I:C/A:CSourcesSingle source
EPSS trend
Probability
0.30%
Chance of exploitation in the next 30 days
Percentile
21%
Versus all other CVEs
30-day change
0.00 pp
From 0.30% on 19-09-2026
19-09-202619-10-2026
EPSS score0.30%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-416Use After FreeThe product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
- CWE-476NULL Pointer DereferenceThe product dereferences a pointer that it expects to be valid but is NULL.
Affected systems
Ubuntu20 products
- linux-aws< 5.4.0-1064.67
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.3All versions (No fix recorded)
- linux-aws-5.4< 5.4.0-1064.67~18.04.1
- linux-aws-5.8All versions (No fix recorded)
Debian1 product
- linux< 5.10.38-1
Fedoraproject1 product
- fedoraEOL34
Nitro_enclaves_project1 product
- nitro_enclaves< 5.10.0
Redhat1 product
5 vendors · 24 products
