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Fencer Intel
medium 5.5

CVE-2021-44421 json

The pointer-validation logic in util/mem_util.rs in Occlum before 0.26.0 for Intel SGX acts as a confused deputy that allows a local attack…

published 4y ago modified 4mo ago also EUVD-2021-31262

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 38%
public exploits
0
none known

Summary

The pointer-validation logic in util/mem_util.rs in Occlum before 0.26.0 for Intel SGX acts as a confused deputy that allows a local attacker to access unauthorized information via side-channel analysis.

Patch / fix

  • occlum_project occlum 0.26.0

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Exploit prediction

0.44% chance of exploitation in the next 30 days, higher than 38% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • github.com https://github.com/occlum/occlum/blob/821ea843ae21037e6cff5268306d2da1fb131552/src/libos/src/util/mem_util.rs#L130 referenced PoC, tagged "exploit" by a source, unverified
  • github.com https://github.com/occlum/occlum/blob/821ea843ae21037e6cff5268306d2da1fb131552/src/libos/src/util/mem_util.rs#L51 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
NVD 2.0 2.1 AV:L/AC:L/Au:N/C:P/I:N/A:N

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.