PatchTheCVECVE-2015-4047: racoon/gssapi.c in IPsec-Tools 0.8.2 allows remote attackers to cause a denial of service (NULL pointer derefe
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HIGH 7.8WATCHLISTDOWNGRADEMITIGATEMITIGATE
CVE-2015-4047 is a high-severity flaw (CVSS 7.8) affecting ipsec-tools, ubuntu linux, fedora. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
racoon/gssapi.c in IPsec-Tools 0.8.2 allows remote attackers to cause a denial of service (NULL pointer dereference and IKE daemon crash) via a series of crafted UDP requests.
Why this priority
- High severity
- EPSS top 4%: very likely to be exploited
- Public exploit reference
- On your watchlist
A fixed release or distro patch exists.
Risk facts
| CVSS score | 7.8 (High) |
| EPSS exploit chance | 9.7% (top 4%) |
| CISA exploited list | No |
| Weakness | CWE-476 |
| Published | 2015-05-29 |
| Last modified | 2026-06-17 |
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
ipsec-tools ipsec-tools DOWNGRADE
Affected: 0.8.2
Fixed in: no fixed release known
Safe to downgrade to: a release before 0.8.2
1. Check installed version
apt-cache policy ipsec-tools || rpm -q ipsec-tools || ipsec-tools --version
2. No fixed release: DOWNGRADE to a release before 0.8.2 (Debian / Ubuntu)
apt-cache madison ipsec-tools
sudo apt install ipsec-tools=<VERSION_BEFORE_0.8.2>
sudo apt-mark hold ipsec-tools
2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)
dnf --showduplicates list ipsec-tools
sudo dnf downgrade ipsec-tools-<VERSION_BEFORE_0.8.2>
sudo dnf versionlock add ipsec-tools
Downgrade risk
Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.
After downgrade
Restart the service, and keep the package held until a fixed release ships.
canonical ubuntu linux MITIGATE
Affected: 12.04
Fixed in: no fixed release known
Safe to downgrade to: a release before 12.04
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
fedoraproject fedora MITIGATE
Affected: 20 · 21
Fixed in: no fixed release known
Safe to downgrade to: a release before 20
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
f5 big-ip application acceleration manager UPGRADE
Affected: >= 11.4.0 and <= 11.6.4 · >= 12.0.0 and <= 12.1.4 · 13.0.0
Fixed in: newer than 12.1.4
Safe to downgrade to: a release before 11.4.0
1. Check installed version
apt-cache policy big-ip-application-acceleration-manager || rpm -q big-ip-application-acceleration-manager || big-ip-application-acceleration-manager --version
2. UPGRADE to newer than 12.1.4 (Debian / Ubuntu)
sudo apt update && sudo apt install --only-upgrade big-ip-application-acceleration-manager
2. UPGRADE (RHEL / Amazon Linux / Fedora)
sudo dnf upgrade big-ip-application-acceleration-manager
Note
Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.
3. If no update is available yet, DOWNGRADE to a release before 11.4.0 (Debian / Ubuntu)
apt-cache madison big-ip-application-acceleration-manager
sudo apt install big-ip-application-acceleration-manager=<VERSION_BEFORE_11.4.0>
sudo apt-mark hold big-ip-application-acceleration-manager
3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)
dnf --showduplicates list big-ip-application-acceleration-manager
sudo dnf downgrade big-ip-application-acceleration-manager-<VERSION_BEFORE_11.4.0>
sudo dnf versionlock add big-ip-application-acceleration-manager
Downgrade risk
Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.
After downgrade
Restart the service, and keep the package held until a fixed release ships.
f5 big-ip local traffic manager UPGRADE
Affected: >= 11.0.0 and <= 11.6.4 · >= 12.0.0 and <= 12.1.4 · 13.0.0
Fixed in: newer than 12.1.4
Safe to downgrade to: a release before 11.0.0
1. Check installed version
apt-cache policy big-ip-local-traffic-manager || rpm -q big-ip-local-traffic-manager || big-ip-local-traffic-manager --version
2. UPGRADE to newer than 12.1.4 (Debian / Ubuntu)
sudo apt update && sudo apt install --only-upgrade big-ip-local-traffic-manager
2. UPGRADE (RHEL / Amazon Linux / Fedora)
sudo dnf upgrade big-ip-local-traffic-manager
Note
Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.
3. If no update is available yet, DOWNGRADE to a release before 11.0.0 (Debian / Ubuntu)
apt-cache madison big-ip-local-traffic-manager
sudo apt install big-ip-local-traffic-manager=<VERSION_BEFORE_11.0.0>
sudo apt-mark hold big-ip-local-traffic-manager
3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)
dnf --showduplicates list big-ip-local-traffic-manager
sudo dnf downgrade big-ip-local-traffic-manager-<VERSION_BEFORE_11.0.0>
sudo dnf versionlock add big-ip-local-traffic-manager
Downgrade risk
Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.
After downgrade
Restart the service, and keep the package held until a fixed release ships.
f5 big-ip advanced firewall manager UPGRADE
Affected: >= 11.3.0 and <= 11.6.4 · >= 12.0.0 and <= 12.1.4 · 13.0.0
Fixed in: newer than 12.1.4
Safe to downgrade to: a release before 11.3.0
1. Check installed version
apt-cache policy big-ip-advanced-firewall-manager || rpm -q big-ip-advanced-firewall-manager || big-ip-advanced-firewall-manager --version
2. UPGRADE to newer than 12.1.4 (Debian / Ubuntu)
sudo apt update && sudo apt install --only-upgrade big-ip-advanced-firewall-manager
2. UPGRADE (RHEL / Amazon Linux / Fedora)
sudo dnf upgrade big-ip-advanced-firewall-manager
Note
Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.
3. If no update is available yet, DOWNGRADE to a release before 11.3.0 (Debian / Ubuntu)
apt-cache madison big-ip-advanced-firewall-manager
sudo apt install big-ip-advanced-firewall-manager=<VERSION_BEFORE_11.3.0>
sudo apt-mark hold big-ip-advanced-firewall-manager
3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)
dnf --showduplicates list big-ip-advanced-firewall-manager
sudo dnf downgrade big-ip-advanced-firewall-manager-<VERSION_BEFORE_11.3.0>
sudo dnf versionlock add big-ip-advanced-firewall-manager
Downgrade risk
Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.
After downgrade
Restart the service, and keep the package held until a fixed release ships.
Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2015-4047?
ipsec-tools: downgrade or apply the listed mitigation; ubuntu linux: mitigate or apply the listed mitigation; fedora: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.
Is CVE-2015-4047 being exploited?
CVE-2015-4047 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2015-4047 affect?
CVE-2015-4047 affects ipsec-tools, ubuntu linux, fedora. Severity is high (CVSS 7.8). racoon/gssapi.c in IPsec-Tools 0.8.2 allows remote attackers to cause a denial of service (NULL pointer dereference and IKE daemon crash) via a series of crafted UDP requests.
How urgent is CVE-2015-4047?
Priority 61/100. High severity; EPSS top 4%: very likely to be exploited; Public exploit reference; On your watchlist
Software pages
Ubuntu vulnerabilities · F5 BIG-IP vulnerabilities
Related CVEs
- CVE-2016-10396 HIGH 7.5 DOWNGRADE The racoon daemon in IPsec-Tools 0.8.2 contains a remotely exploitable computational-complexity attack when pa