⚠ Reference material — not professional advice. Test in staging, back up first, verify against your specific version. Use your own judgment for your environment.
● High · CVSS 7.8 ⚠ ACTIVELY EXPLOITED — CISA KEV

How to Fix CVE-2017-1000253: Security Vulnerability in Kernel

By Sai Kiran Pandrala

⚡ At a glance
SeverityCVSS 7.8 - High
Actively exploited?Yes, listed in CISA KEV (added 2024-09-09)
AffectedKernel (see advisory for affected versions)
Fixed inSee vendor advisory
Type (CWE)Not verified - see official advisory

Patch immediately. CISA added CVE-2017-1000253 to the Known Exploited Vulnerabilities catalog on 2024-09-09. Federal civilian agencies must remediate by 2024-09-30. Treat every internet-reachable instance as a priority patch.

What is CVE-2017-1000253?

CVE-2017-1000253 is a Security Vulnerability flaw in Linux Kernel. It carries a CVSS base score of 7.8 (high). CISA confirmed real-world exploitation by adding it to the Known Exploited Vulnerabilities catalog on 2024-09-09.

From the source record: Linux distributions that have not patched their long-term kernels with https://git.kernel.org/linus/a87938b2e246b81b4fb713edb371a9fa3c5c3c86 (committed on April 14, 2015). This kernel vulnerability was fixed in April 2015 by commit a87938b2e246b81b4fb713edb371a9fa3c5c3c86 (backported to Linux 3.10.77 in May 2015), but it was not recognized as a security threat. With CONFIG_ARCH_BINFMT_ELF_RANDOMIZE_PIE enabled, and a normal top-down address allocation strategy, load_elf_binary() will attempt to map a PIE binary into an address range immediately below mm->mmap_base. Unfortunately, load_elf_ bin...

Why it matters in practice: KEV-listed CVEs draw continuous internet-wide scanning. Any unpatched, internet-reachable installation is on borrowed time. The blast radius depends on how the affected service is exposed. An internet-facing instance with no compensating controls is the highest-risk configuration.

Am I affected?

You are affected if your installation of Kernel matches a version listed in the Affected row above.

On Linux, check the installed package version:


# Debian/Ubuntu
dpkg -l | grep -i kernel
# RHEL/CentOS/Rocky/Fedora
rpm -qa | grep -i kernel
uname -r    # kernel version

How to fix CVE-2017-1000253

Apply the vendor patch. Target the patched build listed on the vendor advisory. The runnable command set below covers the most common deployment patterns for Kernel.

Debian / Ubuntu


sudo apt-get update
sudo apt-get install --only-upgrade kernel
# To check available version first:
apt-cache policy kernel

RHEL / CentOS / Rocky / Alma


sudo dnf upgrade kernel --security -y
# Confirm package version
rpm -q kernel

SUSE


sudo zypper refresh
sudo zypper update --type patch

Complete Bash patch script


#!/usr/bin/env bash
# Patch Kernel for CVE-2017-1000253
set -e
LOG=/var/log/cve-2017-1000253-patch.log
STAMP=$(date +%Y%m%d-%H%M)
exec > >(tee -a "$LOG") 2>&1
echo "[$(date)] starting patch run"

if command -v apt-get >/dev/null; then
  apt-get update
  DEBIAN_FRONTEND=noninteractive apt-get install --only-upgrade -y kernel
elif command -v dnf >/dev/null; then
  dnf upgrade --security -y kernel
elif command -v yum >/dev/null; then
  yum update -y kernel
elif command -v zypper >/dev/null; then
  zypper -n update --type patch
fi

systemctl restart kernel 2>/dev/null || true
echo "[$(date)] patch run complete"

After applying the patch

  1. Restart the service or device so the patched binary loads.
  2. Confirm the running version matches the Fixed in row using the verification command below.
  3. Rotate credentials and API keys that the affected service could access if the asset was exposed during the disclosure window.

If you can't patch immediately

Until the patch lands, narrow the attack surface with these runnable controls.

Block exposure with nftables


sudo nft add table inet filter 2>/dev/null
sudo nft add chain inet filter input "{ type filter hook input priority 0 ; }" 2>/dev/null
sudo nft add rule inet filter input ip saddr 10.10.10.0/24 tcp dport 443 accept
sudo nft add rule inet filter input tcp dport 443 drop

WAF / reverse-proxy snippet

Block requests that look like the exploit pattern at the edge. Tune the regex to the published indicators in the vendor advisory:


# nginx
location / {
    if ($request_uri ~* "(\.\./|%2e%2e|<script|union\s+select)") { return 403; }
    proxy_pass http://backend;
}

Mitigations are temporary. Apply the vendor patch as soon as a maintenance window opens.

How to verify the fix worked

Confirm the patched build is the one actually running.


dpkg -l | grep -i kernel  # Debian/Ubuntu
rpm -q kernel              # RHEL/Rocky/Alma

Expected: the version reported matches See vendor advisory or newer.

Also worth doing: pull recent log windows for any indicators of compromise listed in the vendor advisory, and re-run an authenticated vulnerability scan with up-to-date signatures.

Frequently asked questions

Other vulnerabilities in the same area that are worth patching alongside this one:

Is CVE-2017-1000253 being exploited in the wild?

Yes. CISA added CVE-2017-1000253 to the Known Exploited Vulnerabilities catalog on 2024-09-09. KEV listing means at least one confirmed real-world exploitation report exists.

Do I have to take downtime to patch?

For most Linux Kernel deployments, the patched build needs a service restart or device reboot. HA pairs and clusters can roll the upgrade by patching the standby first, failing over, then patching the former primary.

Will a WAF or IDS rule alone close CVE-2017-1000253?

No. Network filters cut down opportunistic scans but they do not remove the flaw. The vendor patch is the only durable fix.

How quickly should I act on CVE-2017-1000253?

Within the standard patch cycle if the asset is internal-only. Inside one to two weeks for any internet-facing instance, sooner if compensating controls are not in place.

References

*Assembled from the official vendor advisory, the NVD record, and the CISA KEV listing on 2026-05-25. Always confirm against the vendor advisory before applying changes in production.*