CVE-2021-3593: Low severity Libslirp Project Libslirp vulnerability
An invalid pointer initialization issue was found in the SLiRP networking implementation of QEMU. The flaw exists in the udp6input() 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.
Other sources
An invalid pointer initialization issue was found in the SLiRP networking implementation of QEMU. The function udp6input() handles requests for the udp protocol from the guest. While processing a udp packet that is smaller than the size of the udphdr structure it uses memory from outside the working mbuf buffer. This issue may lead to out of bound read access or indirect memory disclosure to the guest.
Upstream commits: https://gitlab.freedesktop.org/slirp/libslirp/-/commit/93e645e7 https://gitlab.freedesktop.org/slirp/libslirp/-/commit/de71c15d
— Red Hat
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
redhat/libslirpto a version that resolves this vulnerability.Fixed in 4.6.0 - Upgrade
Upgrade
debian/libslirpto a version that resolves this vulnerability.Fixed in 4.4.0-1+deb11u2Fixed in 4.7.0-1Fixed in 4.8.0-1 - Upgrade
Upgrade
debian/qemuto a version that resolves this vulnerability.Fixed in 1:5.2+dfsg-11+deb11u3Fixed in 1:5.2+dfsg-11+deb11u2Fixed in 1:7.2+dfsg-7+deb12u12Fixed in 1:10.0.0~rc2+ds-2Fixed in 1:10.0.0~rc3+ds-2 - Upgrade
Upgrade
libslirp/slirpto a version that resolves this vulnerability.Fixed in 4.6.0Patch 93e645e7 - Upgrade
Upgrade
libslirp/slirpto a version that resolves this vulnerability.Fixed in 4.6.0Patch de71c15d
Event History
Frequently Asked Questions
What is the vulnerability ID?
The vulnerability ID is CVE-2021-3593.
What is the severity of CVE-2021-3593?
The severity of CVE-2021-3593 is low.
What is the affected software?
The affected software includes libslirp version up to exclusive 4.6.0, Redhat Enterprise Linux 8.0, Fedora 33 and 34, Debian Debian Linux 9.0, and various versions of Ubuntu and QEMU.
What is the description of CVE-2021-3593?
CVE-2021-3593 is an invalid pointer initialization issue found in the SLiRP networking implementation of QEMU, which could lead to out-of-bounds read access.
How do I fix CVE-2021-3593?
To fix CVE-2021-3593, update libslirp to version 4.6.1 or apply the necessary patches provided by the vendor.