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CVE-2013-4206
Heap-based buffer underflow in the modmul function in sshbn.c in PuTTY before 0.63 allows remote SSH servers to cause a denial of service…
Medium6.8EPSS 2.5%
- Published
- Updated
- Reserved
- Assigned by
- redhat
Description
Heap-based buffer underflow in the modmul function in sshbn.c in PuTTY before 0.63 allows remote SSH servers to cause a denial of service (crash) and possibly trigger memory corruption or code execution via a crafted DSA signature, which is not properly handled when performing certain bit-shifting operations during modular multiplication.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 2.0 | Medium6.8 | AV:N/AC:M/Au:N/C:P/I:P/A:P |
- EPSS (exploitation in 30 days)
- 2.5% · top 15% of all CVEs (4 Nov 2026)
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The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.8.
Weakness
Affected products
n/a
- affected n/a
References (7)
- [oss-security] 20130806 CVE request: three additional flaws fixed in putty 0.63 (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
- 54533 (opens in a new tab)third-party-advisoryx_refsource_SECUNIAx_transferred
- http://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/vuln-modmul.html (opens in a new tab)x_refsource_CONFIRMx_transferred
- DSA-2736 (opens in a new tab)vendor-advisoryx_refsource_DEBIANx_transferred
- openSUSE-SU-2013:1347 (opens in a new tab)vendor-advisoryx_refsource_SUSEx_transferred
- 54379 (opens in a new tab)third-party-advisoryx_refsource_SECUNIAx_transferred
- http://svn.tartarus.org/sgt/putty/sshbn.c?sortby=date&r1=9977&r2=9976&pathrev=9977 (opens in a new tab)x_refsource_CONFIRMx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
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[](https://trackcve.app/cve/CVE-2013-4206)Record last updated .