Medium

Linux kernel TCP session spoofing via IPID collisions

IdentifiersCVE-2020-36516CWE-290

CVE-2020-36516 is a TCP/IP packet-spoofing vulnerability in the Linux kernel through version 5.16.11. The interaction between mixed IPID assignment and hash-based IPID assignment policies enables IP fragmentation and IPID-collision attacks against an existing TCP connection. An attacker can impersonate a packet sender and introduce forged traffic into the connection or disrupt it.

For your environment

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

A successful attacker can compromise the integrity of an existing TCP session by injecting attacker-controlled data, and can impair availability by causing the victim TCP session to terminate. The vulnerability does not inherently provide confidentiality impact.

Mitigation

If you can’t patch tonight, do this now.

Until an updated kernel can be deployed, reduce exposure of TCP services to untrusted networks and use cryptographically protected transport protocols or tunnels that authenticate and integrity-protect application traffic. These measures limit the usefulness of injected TCP payloads but do not correct the kernel IPID behavior.

Remediation

Patch, then assume compromise.

Update to a Linux kernel containing the upstream fix, first identified in Linux kernel 5.17-rc2, or install the applicable vendor kernel security update. For Red Hat Enterprise Linux, fixes were released through RHSA-2022:7444 and RHSA-2022:7683 for RHEL 8 variants, RHSA-2022:7933 and RHSA-2022:8267 for RHEL 9 variants, and RHSA-2024:2674 for RHEL 8.6 Extended Update Support. Reboot after installing an updated kernel. Products outside vendor support scope should be upgraded to a supported release with an available fix.

PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType

LinuxLinux Kerneloperating_system

NetAppBootstrap Osoperating_system

NetAppCloud Volumes Ontap Mediatorapplication

NetAppE-Series Santricity Os Controllerapplication

NetAppH300e Firmwareoperating_system

NetAppH300s Firmwareoperating_system

NetAppH410c Firmwareoperating_system

NetAppH410s Firmwareoperating_system

NetAppH500e Firmwareoperating_system

NetAppH500s Firmwareoperating_system

NetAppH610c Firmwareoperating_system

NetAppH610s Firmwareoperating_system

NetAppH615c Firmwareoperating_system

NetAppH700e Firmwareoperating_system

NetAppH700s Firmwareoperating_system

NetAppSolidfire & Hci Management Nodeapplication

NetAppSolidfire, Enterprise Sds & Hci Storage Nodeapplication

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

ACTIVITY FEED

Recent activity

7 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.

7 SOURCESView more in app

redhat accessNews

Jan 1, 2026

RHSA-2022:7933 - Security Advisory - Red Hat Customer Portal

Linux kernel TCP vulnerability enabling an off-path attacker to inject data into, or terminate, a victim TCP session.

redhat accessNews

Jan 1, 2026

RHSA-2022:8267 - Security Advisory - Red Hat Customer Portal

Linux kernel TCP-session injection or termination vulnerability.

redhat accessNews

Jan 1, 2026

RHSA-2022:7683 - Security Advisory - Red Hat Customer Portal

Linux kernel TCP vulnerability allowing an off-path attacker to inject data into, or terminate, a victim TCP session.

redhat accessNews

Jan 1, 2026

RHSA-2022:7444 - Security Advisory - Red Hat Customer Portal

Linux kernel TCP vulnerability allowing off-path data injection or TCP-session termination.

+3 more in the timeline

What this page doesn’t show

The version that knows your environment.

This page is what’s public. Mallory adds the parts that aren’t: which of your assets are affected, which adversaries are exploiting it right now, which detections to deploy, and what to do tonight.

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Exposure mapping

Query your assets running an affected version, and investigate the blast radius.

Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity