CVE-2021-3593
This issue may lead to out-of-bounds read access or indirect host memory disclosure to the guest.
Does this matter?
Lower severity and a low EPSS score (0.33%). Track it; it rarely justifies an emergency change on its own.
Description
An invalid pointer initialization issue was found in the SLiRP networking implementation of QEMU. The flaw exists in the udp6_input() function and could occur while processing a udp packet that is smaller than the size of the 'udphdr' structure. This issue may lead to out-of-bounds read access or indirect host memory disclosure to the guest. The highest threat from this vulnerability is to data confidentiality. This flaw affects libslirp versions prior to 4.6.0.
- CVSS 3.1
- 3.8 LOWCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N
- EPSS
- 0.33% probability · 25th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-824
- Affected
- libslirp project/libslirp · redhat/enterprise linux · fedoraproject/fedora · debian/debian linux
- Source
- secalert@redhat.com
EPSS 0.3% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://bugzilla.redhat.com/show_bug.cgi?id=1970487Issue Tracking, Patch, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2022/04/msg00002.htmlMailing List, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2023/03/msg00013.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GCKWZWY64EHTOQMLVLTSZ4AA27EWRJMH/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SGPQZFVJCFGDSISFXPCQTTBBD7QZLJKI/
- https://security.gentoo.org/glsa/202107-44Third Party Advisory
- https://security.netapp.com/advisory/ntap-20210805-0004/Third Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1970487Issue Tracking, Patch, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2022/04/msg00002.htmlMailing List, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2023/03/msg00013.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GCKWZWY64EHTOQMLVLTSZ4AA27EWRJMH/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SGPQZFVJCFGDSISFXPCQTTBBD7QZLJKI/
- https://security.gentoo.org/glsa/202107-44Third Party Advisory
- https://security.netapp.com/advisory/ntap-20210805-0004/Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.