Look up another CVE · open CVE-2021-22555 in the interactive tracker
CVE-2021-22555
A heap out-of-bounds write affecting Linux since v2.6.19-rc1 was discovered in net/netfilter/x_tables.c
The kernel CNA record carries no publication date. Subsystem unknown. Debian urgency: not yet assigned.
What to do, per Debian release
Debian's own status for CVE-2021-22555 in every release this site tracks, and what each one means in practice. Every status below is the one the Debian Security Team publishes for this CVE. source
| Release | Status | Version | What this means |
|---|---|---|---|
| Debian 12bookworm | fixed | 5.10.38-1 | Update the kernel and reboot. Fixed in 5.10.38-1. A running kernel keeps the old code until the machine restarts. |
| Debian 13trixie | fixed | 5.10.38-1 | Update the kernel and reboot. Fixed in 5.10.38-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 5.10.38-1 | Update the kernel and reboot. Fixed in 5.10.38-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 5.10.38-1 | Update the kernel and reboot. Fixed in 5.10.38-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
A heap out-of-bounds write affecting Linux since v2.6.19-rc1 was discovered in net/netfilter/x_tables.c. This allows an attacker to gain privileges or cause a DoS (via heap memory corruption) through user name space
Where it lives
Show whether Debian builds this, per release
Not established. This site could not find the build rule for the affected file in the kernel trees Debian ships, so it has no answer about whether Debian compiles this code. Read that as unknown, never as absent.
- bookworm, trixie, forky, sid?
- ?
- not established - no Makefile entry for the affected file
Where a release above reads "not established", no build rule for the affected file was found in that release's kernel tree. That is a gap in this lookup, not a finding that the code is absent.
From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.
Known to be exploited in the wild
- Added to KEV
- 2025-10-06
- Federal due date
- 2025-10-27
- Ransomware use
- unknown
- Required action
- Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Signals
- Published
- unknown
- CVSS
- no vector published, unrated
- Attack vector
- not published
- EPSS
- 78.68%, higher than 99.6% of all CVEssource
- CISA KEV
- listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- Subsystem
- unknown
Why the CNA scored it this way
The kernel CNA published no CVSS vector and no reasoning for CVE-2021-22555, which is why it is shown as unrated rather than given an invented score. 6,405 of the 20,413 CVEs here carry reasoning; this is not one of them.