Denial of service in QEMU

1) Infinite loop

EUVDB-ID: #VU59085

Risk: Medium

CVSSv3.1: 6.7 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-20257

CWE-ID: CWE-835 - Loop with Unreachable Exit Condition ('Infinite Loop')

Exploit availability: No

Description

The vulnerability allows a remote user to perform a denial of service (DoS) attack.

The vulnerability exists due to infinite loop in the e1000 NIC emulator when processing transmits (tx) descriptors in process_tx_desc of QEMU. A remote user can consume all available CPU resources and cause denial of service conditions.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

QEMU: 6.0.0 - 6.1.0

External links

http://lists.gnu.org/archive/html/qemu-devel/2021-02/msg03595.html
http://bugzilla.redhat.com/show_bug.cgi?id=1930087

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to trick the victim to open a a specially crafted file.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.