CVE-2013-2053: Buffer overflow in the atodn function in Openswan before 2.6.39, when Opportunistic Encryption is enabled and

Q: How do I fix CVE-2013-2053?

openswan: upgrade to newer than 2.6.38. Exact commands for each OS are on this page.

Q: Is CVE-2013-2053 being exploited?

CVE-2013-2053 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2013-2053 affect?

CVE-2013-2053 affects openswan. Severity is medium (CVSS 6.8). Buffer overflow in the atodn function in Openswan before 2.6.39, when Opportunistic Encryption is enabled and an RSA key is being used, allows remote attackers to cause a denial of service (pluto IKE daemon crash) and possibly execute arbit

Q: How urgent is CVE-2013-2053?

Priority 45/100. No elevated risk signals yet.

This month

MEDIUM 6.8UPGRADE

CVE-2013-2053 is a medium-severity flaw (CVSS 6.8) affecting openswan. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Buffer overflow in the atodn function in Openswan before 2.6.39, when Opportunistic Encryption is enabled and an RSA key is being used, allows remote attackers to cause a denial of service (pluto IKE daemon crash) and possibly execute arbitrary code via crafted DNS TXT records. NOTE: this might be the same vulnerability as CVE-2013-2052 and CVE-2013-2054.

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	6.8 (Medium)
EPSS exploit chance	2.4% (top 16%)
CISA exploited list	No
Weakness	CWE-119
Published	2013-07-09
Last modified	2026-06-16

Publisher (CNA): Red Hat, Inc. · Vendor: xelerance

Last updated 2026-06-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2013-07-09 17:55 UTCPublished CVE record published
2026-06-16 23:52 UTCUpdated Record last modified

xelerance openswan UPGRADE

Affected: <= 2.6.38 · 2.6.01 · 2.6.02 · 2.6.03 · 2.6.04 · 2.6.05 · 2.6.06 · 2.6.07

Fixed in: newer than 2.6.38

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy openswan || rpm -q openswan || openswan --version

2. UPGRADE to newer than 2.6.38 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade openswan

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade openswan

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

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.

Quick answers

How do I fix CVE-2013-2053?

openswan: upgrade to newer than 2.6.38. Exact commands for each OS are on this page.

Is CVE-2013-2053 being exploited?

CVE-2013-2053 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-2013-2053 affect?

CVE-2013-2053 affects openswan. Severity is medium (CVSS 6.8). Buffer overflow in the atodn function in Openswan before 2.6.39, when Opportunistic Encryption is enabled and an RSA key is being used, allows remote attackers to cause a denial of service (pluto IKE daemon crash) and possibly execute arbit

How urgent is CVE-2013-2053?

Priority 45/100. No elevated risk signals yet.

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CVE-2018-15836 HIGH 7.5 UPGRADE In verify_signed_hash() in lib/liboswkeys/signatures.c in Openswan before 2.6.50.1, the RSA implementation doe
CVE-2014-2037 MEDIUM 5.0 DOWNGRADE Openswan 2.6.40 allows remote attackers to cause a denial of service (NULL pointer dereference and IKE daemon
CVE-2013-6466 MEDIUM 5.0 UPGRADE Openswan 2.6.39 and earlier allows remote attackers to cause a denial of service (NULL pointer dereference and
CVE-2011-4073 MEDIUM 4.0 DOWNGRADE Use-after-free vulnerability in the cryptographic helper handler functionality in Openswan 2.3.0 through 2.6.3

References

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