CVE-2017-2620

Severity: critical (CVSS 9.9 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 3.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2018-07-27 · updated 2026-06-17
Weakness: CWE-787

Description

Quick emulator (QEMU) before 2.8 built with the Cirrus CLGD 54xx VGA Emulator support is vulnerable to an out-of-bounds access issue. The issue could occur while copying VGA data in cirrus_bitblt_cputovideo. A privileged user inside guest could use this flaw to crash the QEMU process OR potentially execute arbitrary code on host with privileges of the QEMU process.

Affected products

Citrix XenServer: 6.2.0-sp1, 6.5-sp1; 6.0.2, 7.0, 7.1 (and their updates)
Debian Linux: 7.0 (and their updates)
QEMU: before 2.8.0 — fixed in 2.8.0
RedHat Enterprise Linux Desktop: 6.0, 7.0 (and their updates)
RedHat Enterprise Linux Server: 6.0, 7.0 (and their updates)
RedHat Enterprise Linux Server Aus: 7.3, 7.4 (and their updates)
RedHat Enterprise Linux Server Eus: 7.3, 7.4, 7.5 (and their updates)
RedHat Enterprise Linux Workstation: 6.0, 7.0 (and their updates)
OpenStack: 5.0, 6.0, 7.0, 8, 9, 10 (and their updates)
xen: through 4.7.1; 4.7.1-r1, 4.7.1-r2, 4.7.1-r3, 4.7.1-r4, 4.7.1-r5, 4.7.1-r6 (+1)
QEMU: 2.8

How to fix

Upgrade to a fixed version: QEMU 2.8.0. Check the vendor advisory for mitigations.

References

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