CVE-2021-3593
An invalid pointer initialization issue was found in the SLiRP networking implementation of QEMU. The flaw exists in the udp6_input()…
- Published
- Updated
- Reserved
- Assigned by
- redhat
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.
Timeline
ID reserved
By redhat
- 5 days later
· 5 days later
Published
- 3 years later
· 3 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 3.1 | Low3.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N |
- EPSS (exploitation in 30 days)
- 0.33% · top 74% of all CVEs (7 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Low 3.8.
Weakness
Affected products
QEMU
- affected libslirp 4.6.0
References (7)
- https://bugzilla.redhat.com/show_bug.cgi?id=1970487 (opens in a new tab)x_transferred
- FEDORA-2021-71de23bedd (opens in a new tab)vendor-advisoryx_transferred
- FEDORA-2021-7cd749f133 (opens in a new tab)vendor-advisoryx_transferred
- GLSA-202107-44 (opens in a new tab)vendor-advisoryx_transferred
- https://security.netapp.com/advisory/ntap-20210805-0004/ (opens in a new tab)x_transferred
- [debian-lts-announce] 20220404 [SECURITY] [DLA 2970-1] qemu security update (opens in a new tab)mailing-listx_transferred
- [debian-lts-announce] 20230314 [SECURITY] [DLA 3362-1] qemu security update (opens in a new tab)mailing-listx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2021-3593)Record last updated .