CVE-2021-3594: 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 udpinput() 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 udpinput() 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/74572be4
— 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+deb11u4Fixed in 1:7.2+dfsg-7+deb12u12Fixed in 1:10.0.0~rc3+ds-2Fixed in 1:10.0.0+ds-1 - Upgrade
Upgrade
libslirpto a version that resolves this vulnerability.Fixed in 4.6.0
Event History
Frequently Asked Questions
What is CVE-2021-3594?
CVE-2021-3594 is an invalid pointer initialization issue found in the SLiRP networking implementation of QEMU.
What is the severity of CVE-2021-3594?
The severity of CVE-2021-3594 is low (CVSS score of 3.8).
How does the vulnerability in CVE-2021-3594 occur?
The vulnerability in CVE-2021-3594 occurs in the udp_input() function of the SLiRP networking implementation in QEMU while processing a udp packet that is smaller than the size of the 'udphdr' structure.
What are the possible impacts of CVE-2021-3594?
CVE-2021-3594 may lead to out-of-bounds read access or potential code execution.
How can I mitigate CVE-2021-3594?
To mitigate CVE-2021-3594, it is recommended to update the affected software to version 4.6.0 or apply the appropriate security patches provided by the vendor.