Vulnerability · Published May 26, 2021 · Assigned by redhat

CVE-2021-20177

Medium 4.4

In plain English

A medium-severity out-of-bounds read in kernel. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 21% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)4.4Medium
Exploit odds (30 days)0.3%top 79.1% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known

Official description

A flaw was found in the Linux kernel's implementation of string matching within a packet. A privileged user (with root or CAP_NET_ADMIN) when inserting iptables rules could insert a rule which can panic the system. Kernel before kernel 5.5-rc1 is affected.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux5.5.13-1DEBIAN-CVE-2021-20177
Debian:13linux5.5.13-1DEBIAN-CVE-2021-20177
Debian:14linux5.5.13-1DEBIAN-CVE-2021-20177
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2021-20177
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2021-20177
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2021-20177

Affected products (as reported)

VendorProductVersions
n/a kernel kernel 5.5-rc1

Weakness: CWE-125

References