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Not in CISA KEV
CRITICAL severity

CVE-2013-7459 pycrypto

CRITICALFix: dlitz/pycrypto@8dbe0dc

CVE-2013-7459 is a critical-severity (CVSS 9.8) Buffer Overflow vulnerability in pycrypto. 1 public exploit reference exists, so weaponization risk is real. No vendor fix is recorded yet; mitigation options are listed below.

Buffer Overflow in pycrypto

Also known asPYSEC-2017-94
Published
Dec 14, 2018
Updated
Oct 18, 2024
Affected
1 pkg
Patched
See advisory
Exploits
1 known
Exploitation data as of Sep 18, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗
9.6%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs95th percentile — riskier than 95% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

How urgent is this, really

CVE-2013-7459 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.

Where this sits among everything scored

Of 377,166 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.

Real-World Exposure

1 pkg affected
🐍pycrypto

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

Heap-based buffer overflow in the ALGnew function in block_templace.c in Python Cryptography Toolkit (aka pycrypto) allows remote attackers to execute arbitrary code as demonstrated by a crafted iv parameter to cryptmsg.py.

Affected Packages

1 total
EcosystemPackageVulnerable rangeFix
🐍PyPIpycryptoall versionsNo fix
Exploits & PoCs
1

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pycrypto, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Remediation status

    No patched version of pycrypto has shipped for CVE-2013-7459 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.

  3. Mitigate without a patch

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2013-7459 can be triaged on real exposure rather than presence alone.

Tailored to CVE-2013-7459. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Frequently Asked Questions

Heap-based buffer overflow in the ALGnew function in block_templace.c in Python Cryptography Toolkit (aka pycrypto) allows remote attackers to execute arbitrary code as demonstrated by a crafted iv parameter to cryptmsg.py.
O3 Security · Impact-Aware SCA

Is CVE-2013-7459 in your dependencies?

O3 Security finds CVE-2013-7459 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

CVE-2013-7459: pycrypto RCE (Critical 9.8) | O3 Security