CVE-2018-3639

CVE-2018-3639 is a medium-severity vulnerability in Intel Atom C with a CVSS 3.x base score of 5.5. Its EPSS exploit-prediction score of 61% places it in the 99th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-203.

Key facts

• Severity: Medium (CVSS 3.x base score 5.5)
• CVSS v2: 2.1
• EPSS exploit prediction: 61% (99th percentile)
• Actively exploited: Not listed in CISA KEV
• Weakness: CWE-203
• Affected product: Intel Atom C
• Published: 2018-05-22
• Last modified: 2026-06-17

Description

Systems with microprocessors utilizing speculative execution and speculative execution of memory reads before the addresses of all prior memory writes are known may allow unauthorized disclosure of information to an attacker with local user access via a side-channel analysis, aka Speculative Store Bypass (SSB), Variant 4.

Frequently asked questions

What is CVE-2018-3639?

Systems with microprocessors utilizing speculative execution and speculative execution of memory reads before the addresses of all prior memory writes are known may allow unauthorized disclosure of information to an attacker with local user access via a side-channel analysis, aka Speculative Store Bypass (SSB), Variant 4.

How severe is CVE-2018-3639?

CVE-2018-3639 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2018-3639 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 61% (99th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-3639?

CVE-2018-3639 primarily affects Intel Atom C. In total, 626 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2018-3639?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2018-3639 published?

CVE-2018-3639 was published on 2018-05-22 and last updated on 2026-06-17.

References

• http://lists.opensuse.org/opensuse-security-announce/2019-05/msg00058.html
• http://lists.opensuse.org/opensuse-security-announce/2019-05/msg00059.html
• http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00007.html
• http://support.lenovo.com/us/en/solutions/LEN-22133
• http://www.fujitsu.com/global/support/products/software/security/products-f/cve-2018-3639e.html
• http://www.openwall.com/lists/oss-security/2020/06/10/1
• http://www.openwall.com/lists/oss-security/2020/06/10/2
• http://www.openwall.com/lists/oss-security/2020/06/10/5
• http://www.securityfocus.com/bid/104232
• http://www.securitytracker.com/id/1040949
• http://www.securitytracker.com/id/1042004
• http://xenbits.xen.org/xsa/advisory-263.html
• https://access.redhat.com/errata/RHSA-2018:1629
• https://access.redhat.com/errata/RHSA-2018:1630
• https://access.redhat.com/errata/RHSA-2018:1632
• https://access.redhat.com/errata/RHSA-2018:1633
• https://access.redhat.com/errata/RHSA-2018:1635
• https://access.redhat.com/errata/RHSA-2018:1636
• https://access.redhat.com/errata/RHSA-2018:1637
• https://access.redhat.com/errata/RHSA-2018:1638
• https://access.redhat.com/errata/RHSA-2018:1639
• https://access.redhat.com/errata/RHSA-2018:1640
• https://access.redhat.com/errata/RHSA-2018:1641
• https://access.redhat.com/errata/RHSA-2018:1642
• https://access.redhat.com/errata/RHSA-2018:1643
• https://access.redhat.com/errata/RHSA-2018:1644
• https://access.redhat.com/errata/RHSA-2018:1645
• https://access.redhat.com/errata/RHSA-2018:1646
• https://access.redhat.com/errata/RHSA-2018:1647
• https://access.redhat.com/errata/RHSA-2018:1648

Affected products (626)

• cpe:2.3:h:intel:atom_c:c2308:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_c:c3308:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_c:c3338:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_c:c3508:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_c:c3538:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_c:c3558:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_c:c3708:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_c:c3750:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_c:c3758:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_c:c3808:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_c:c3830:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_c:c3850:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_c:c3858:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_c:c3950:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_c:c3955:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_c:c3958:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_e:e3805:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_e:e3815:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_e:e3825:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_e:e3826:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_e:e3827:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_e:e3845:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_x5-e3930:-:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_x5-e3940:-:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_x7-e3950:-:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_z:z2420:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_z:z2460:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_z:z2480:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_z:z2520:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_z:z2560:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_z:z2580:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_z:z2760:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_z:z3460:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_z:z3480:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_z:z3530:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_z:z3560:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_z:z3570:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_z:z3580:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_z:z3590:*:*:*:*:*:*:*
• cpe:2.3:h:intel:atom_z:z3735d:*:*:*:*:*:*:*

More vulnerabilities in Intel Atom C

• CVE-2018-3652 — High (CVSS 7.6): Existing UEFI setting restrictions for DCI (Direct Connect Interface) in 5th and 6th generation Intel Xeon Processor E3…
• CVE-2018-3693 — Medium (CVSS 5.6): Systems with microprocessors utilizing speculative execution and branch prediction may allow unauthorized disclosure of…
• CVE-2018-3640 — Medium (CVSS 5.6): Systems with microprocessors utilizing speculative execution and that perform speculative reads of system registers may…
• CVE-2018-9056 — Medium (CVSS 5.6): Systems with microprocessors utilizing speculative execution may allow unauthorized disclosure of information to an…
• CVE-2017-5754 — Medium (CVSS 5.6): Systems with microprocessors utilizing speculative execution and indirect branch prediction may allow unauthorized…
• CVE-2017-5753 — Medium (CVSS 5.6): Systems with microprocessors utilizing speculative execution and branch prediction may allow unauthorized disclosure of…

All CVEs affecting Intel Atom C →

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Browse all CWE-203 (Observable Discrepancy) vulnerabilities →