CVE-2025-47268 Ping Vulnerability: Azure Linux Risk and Mitigation

Microsoft's public attestation that the iputils "ping" utility is vulnerable to CVE-2025-47268 correctly identifies Azure Linux as a confirmed, Microsoft-maintained product shipping the affected component — but it is not, and should not be read as, an exclusive list: any Microsoft-supplied artifact that embeds a Linux userland or a third‑party Linux distribution may also contain the vulnerable iputils binary and therefore be potentially affected until patched.

Background / Overview​

In May 2025 the upstream iputils project and multiple vulnerability trackers published a report describing a signed 64‑bit integer overflow in the ping utility’s timestamp multiplication logic. The vulnerability can be triggered by a crafted ICMP Echo Reply packet and results in application errors or incorrect statistics collection — in the worst case crashing the ping process and creating a local denial‑of‑service condition. Upstream iputils released a code change to address the bug in the release dated 20250602; individual Linux distributions and product vendors have been issuing their own patches and package updates on different timelines.
Microsoft’s security guide and transparency push have explicitly called out Azure Linux (Microsoft’s CBL‑Mariner‑based distribution and the Azure Linux container host used on AKS and other services) as a product that includes iputils and is therefore confirmed affected. Microsoft also announced a policy of publishing machine-readable VEX/CSAF attestations for Azure Linux and said it will update those attestations if additional Microsoft products are identified as shipping the same vulnerable component.
This article explains the technical fault, reasons why Azure Linux is not necessarily the only Microsoft product that might carry the vulnerable code, the pragmatic steps IT operators and developers should take now, and how to triage and mitigate risk across cloud, container, and developer environments.

---

How the vulnerability works (technical explanation)​

The root cause in simple terms​

• The bug arises inside the ping utility’s handling of timestamps when it multiplies a signed 64‑bit integer during round‑trip time (RTT) calculations.
• Under certain crafted input conditions — notably specially formulated ICMP Echo Reply packets — the timestamp multiplication can overflow the signed 64‑bit integer type.
• When that overflow occurs the program can behave incorrectly, produce wrong statistics, or crash entirely, causing a denial of service for the ping process.

Exploitation vector and practical implications​

• The vulnerability is network‑facing in the sense that a remote host can send specially crafted ICMP Echo Reply packets that will be processed by a vulnerable ping instance on a victim machine.
• Typical exploitation scenarios include:
• An attacker lures or tricks a victim into using ping against an attacker‑controlled target (for example, by poisoning DNS responses or via social engineering).
• A compromised host on the same network or on the path sends responses crafted to trigger the overflow while the victim issues ping probes.
• A successful exploit affects the local ping process (DoS) and data collection (wrong RTT statistics). It does not directly imply remote code execution or kernel compromise; it is a userland integer overflow in a diagnostic utility.

---

Versions and patch status — what to look for​

• Upstream iputils fixed the issue in the release labeled 20250602. Any iputils installation that is older than that upstream tag is potentially vulnerable unless a downstream vendor has backported equivalent fixes.
• Several Linux distributions published security advisories and package updates; however, distribution package names and versioning vary (for example, iputils, iputils‑ping, or distro‑specific packaging).
• Some distros referenced earlier upstream releases as the affected range (e.g., through 20240905) because of differences in how they packaged or updated iputils; others moved to fixes sooner by shipping backports.

Important operational takeaway: you cannot rely solely on the upstream release tag; verify the package version and vendor advisory for the specific distribution or image you run, because downstream packaging timelines differ.

---

Is Azure Linux the only Microsoft product that includes iputils?​

Short answer: No — but Microsoft has confirmed Azure Linux as the first Microsoft‑maintained product that ships the vulnerable iputils component and is actively publishing machine‑readable attestations for it. Microsoft’s statement that it will update the CVE mapping if further products are found to include the component is accurate; however, it is not proof that no other Microsoft product contains iputils.
Why that matters:

• Microsoft maintains and publishes Azure Linux (the CBL‑Mariner derivative) as a host OS image for workloads such as AKS node pools, Azure container hosts, and other Azure services. Those images have been explicitly attested.
• Microsoft does not ship Linux userland in native Windows desktop or Windows Server components; however, Microsoft delivers and supports many artifacts that can and do contain Linux userland:
• AKS node images and managed node pools (which may use Azure Linux or other distributions) — node images can include iputils depending on the OS SKU.
• Azure Marketplace images and partner appliances — these are often third‑party VM images that run distributions where iputils is commonly present.
• Microsoft container images and development container base images — official Microsoft container artifacts (for example, devcontainers and some language runtime images) are built from upstream distributions and may include iputils, depending on the base image and image maintainer.
• Windows Subsystem for Linux (WSL) distributions — WSL provides Linux userland environments; distributions available through the Microsoft Store (Ubuntu, Debian, etc.) are maintained by their respective vendors, and their iputils package status will follow those vendors’ advisories. Microsoft ships the WSL kernel, not the Linux userland packages.
• CBL‑Mariner variants used internally — any internal Microsoft service built on Mariner could include iputils unless stripped from the image.

In short: Microsoft’s attestation is an authoritative confirmation for Azure Linux, but it is not a sweeping exclusion of other Microsoft artifacts. Product owners and operators need to treat the attestation as a starting point and perform their own inventory and verification for images, containers, node pools, and developer environments under their control.

---

Where to look inside a Microsoft environment​

When deciding whether a Microsoft-supplied or Microsoft-hosted artifact in your estate is affected, prioritize checking:

• AKS node pools (verify the OS SKU: Azure Linux vs Ubuntu vs custom image).
• Marketplace VM images used to host workloads in Azure and any vendor appliances.
• Microsoft‑published container images and developer/devcontainer images your teams consume.
• WSL distributions running on developer machines (ensure distro packages are updated).
• Any CBL‑Mariner‑based images you built from Microsoft sources or forked for internal use.

Remember: if the guest OS or container image is based on a distribution whose package set includes iputils (ping), it's likely present unless the image intentionally removed it.

---

Practical detection and verification steps​

Use the following commands and checks to quickly find iputils and establish its version on common Linux families. Run these in shells for the target host, container, or VM image:

• Debian/Ubuntu based systems:
• Check installed package: dpkg -l | grep -E 'iputils|iputils-ping'
• Check version: ping -V (the binary often prints the iputils version) or apt-cache policy iputils-ping
• Upgrade: sudo apt update && sudo apt install --only-upgrade iputils-ping
• RHEL / CentOS / Fedora / AlmaLinux:
• Check installed package: rpm -qa | grep iputils
• Version: ping -V or rpm -qi iputils
• Upgrade: sudo dnf update iputils (or yum update iputils on older systems)
• SUSE:
• Check: rpm -qa | grep iputils
• Upgrade: sudo zypper refresh && sudo zypper update iputils
• CBL‑Mariner / Azure Linux:
• Check: tdnf list installed | grep iputils or rpm -qa | grep iputils
• Upgrade: sudo tdnf update iputils (or follow your managed image update path if using image-based upgrades)
• Alpine (if using in containers):
• Check: apk info | grep iputils
• Upgrade: sudo apk update && sudo apk add --upgrade iputils

Container images and build pipelines:

• Inspect Dockerfile or image layers for iputils or iputils‑ping packages.
• For images in registries, extract packages with container scanning or docker run --rm IMAGE dpkg -l | grep iputils (for Debian-based images) or equivalent checks for the image’s package manager.
• Rebuild images with updated base packages or remove the ping binary as a temporary mitigation.

If you have large fleets, export inventory via configuration management or container registry scanners and search for package names. Microsoft’s published VEX/CSAF attestations for Azure Linux are a helpful starting point — but you should not treat them as a full inventory for your tenant's artifacts.

---

Mitigations and immediate remediation steps​

If you find vulnerable versions in your environment, prioritize remediation as follows:

• Patch first
• Apply the vendor or distribution package update that contains the iputils fix (upstream fix is in the 20250602 release; downstream distros may have backports).
• For Azure Linux (CBL‑Mariner) nodes, use the platform’s update mechanism (tdnf or the managed image release) to install the patched iputils build or apply the image refresh Microsoft provides.
• If patching is not immediately possible, apply temporary mitigations
• Remove or restrict ping:
• Remove the ping binary from images or hosts: sudo apt remove iputils-ping or sudo dnf remove iputils.
• For containers, rebuild without iputils/ping to reduce the attack surface.
• For developer WSL instances, consider removing the package or instructing developers to update their distro packages.
• Limit ICMP traffic:
• Use network ACLs, host firewalls, or perimeter devices to block untrusted ICMP Echo Reply packets.
• Note: Blocking all ICMP is not recommended long‑term because ICMP serves diagnostic and path MTU functions — instead block or filter ICMP Echo Reply packets from untrusted or public networks where feasible.
• Container isolation:
• Enforce strict network policies for pods and containers so that only trusted endpoints can send ICMP responses.
• Detect and monitor
• Look for crashes or abnormal termination of ping processes in system logs and monitoring systems.
• Monitor for unusual ICMP traffic patterns with network IDS/flow monitoring.
• If you use container scanning or vulnerability management tooling, ensure the iputils CVE is being tracked and that remediation tickets are created.
• Update CI/CD and image pipelines
• Rebuild affected container images with patched package versions.
• Pin or update base images to releases that include the fix.
• Add checks to CI to fail builds that depend on vulnerable package versions.

---

Risk assessment for different environments​

• Developer workstations and WSL: Medium risk. Developer machines running WSL with vulnerable distro packages are exposed primarily to local or internal networks; however, developers are a high‑risk population for social engineering, and compromised developer machines are valuable for attackers.
• Containers used for CI/CD: Elevated risk. Build agents that run as long‑lived containers or VMs might be coaxed into probing attacker hosts, and compromised or unstable tooling can interrupt development.
• Production servers (VMs and AKS node pools): High operational impact if ping is used by monitoring tools and the crash causes monitoring gaps or false negatives. The direct security impact to confidentiality is low, but availability of diagnostics and monitoring can be degraded.
• Network appliances and third‑party images: Variable risk. Marketplace images or third‑party appliances running Linux-based UIs may include iputils; their patching cadence can vary and should be validated.

---

What customers should do right now — checklist​

• Inventory:
• Search for iputils / ping across your VM, container, and WSL inventories.
• For AKS, check the node OS SKU and whether node images are Azure Linux or other distros.
• Patch:
• Apply the patch from your distro/vendor. For Azure Linux, follow the managed update path or apply the patched package from Microsoft’s repositories.
• Rebuild images:
• Rebuild and redeploy container images that included iputils before the patched version was available.
• Temporary mitigations:
• Remove ping from systems where it is not required.
• Filter ICMP Echo Reply from untrusted networks at network edge devices.
• Monitor:
• Add alerts for unexpected ping crashes and for unusual ICMP traffic.
• Policy:
• Update CI/CD policies to avoid shipping unpatched package versions and to include vulnerability scanning for these types of userland tools.
• Track vendor attestations:
• Monitor the vendor VEX/CSAF attestations (Microsoft has committed to publishing and expanding them for Azure Linux) and vendor advisories to learn when new Microsoft products are confirmed to ship the affected component.

---

Why Microsoft’s VEX/CSAF approach matters — and its limits​

Microsoft’s move to publish machine‑readable VEX/CSAF attestations for Azure Linux is a significant step in transparency: it gives customers clear, automatable data about which CVEs the vendor confirms for a product and under what mitigations or conditions. That helps reduce noisy alerts and shortens triage cycles.
However, VEX/CSAF attestations are only as comprehensive as the vendor’s mapping of product components. Customers should not rely on an attestation for a single Microsoft product as proof that no other Microsoft artifact contains a given open source component. Microsoft has acknowledged this explicitly: the attestation for Azure Linux is a starting point and will be updated if further products are identified. Until you have inventory‑level confirmation for your images and artifacts, you should assume the potential for exposure and validate accordingly.

---

A few closing operational notes and cautions​

• Different package names and backporting strategies mean identical CVE identifiers can have different remediation timelines per distribution and per product image. Always verify the distro or product advisory tied to the package version you run.
• The vulnerability affects the ping utility in userland, not the kernel network stack itself. This limits the severity to denial‑of‑service of ping and incorrect diagnostic data rather than direct system compromise — nevertheless the operational impact (lost monitoring telemetry, developer disruption, container instability) can be meaningful.
• Do not assume that managed Microsoft services are automatically immune; while Microsoft manages and patches many platform images, customers often run custom images, partner images from the Marketplace, or containers built by third parties — these are the sources that most often cause gaps between vendor attestations and tenant exposures.
• For large fleets, automate detection: leverage your container registries, image scanners, CMDBs, and host management tooling to find and remediate instances of the vulnerable package at scale.

---

Conclusion​

CVE‑2025‑47268 is a real, demonstrable bug in the iputils ping utility that upstream fixed in the 20250602 release. Microsoft’s confirmation that Azure Linux (the CBL‑Mariner‑derived distribution used across AKS and other Azure services) ships the affected iputils component is an important and authoritative data point — but it is not an all‑clear for the rest of a customer’s Microsoft‑hosted or Microsoft‑supplied artifacts.
Operators and developers should assume that any Linux userland under their control — whether running in Azure VMs, AKS nodes, containers, WSL, or Marketplace images — could include the vulnerable ping binary. The immediate, practical actions are clear: inventory your images and hosts, apply the vendor/distro patches (or rebuild images), apply temporary mitigations where necessary, and watch Microsoft’s published attestations as they evolve.
The vulnerability is not a catastrophic escalation risk in isolation, but its operational impact on monitoring, diagnostics, and developer productivity can be significant. Treat the issue with urgency: patch quickly, harden network controls where appropriate, and bake package‑level scanning and rebuilds into your CI/CD pipeline so the next vulnerability in a ubiquitous diagnostic tool does not catch you off guard.

---

Source: MSRC Security Update Guide - Microsoft Security Response Center