CVE-2013-4208· NVD / CVE Program· CNA redhat

The rsa_verify function in PuTTY before 0.63 (1) does not clear sensitive process memory after use and (2) does not free certain structures

Noroxi assessment

Priority: Monitor (action score 8/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.38% (FIRST EPSS).
No special conditions are required; it is repeatable.
Fixed version: filezilla (Debian:12) 3.7.3-1; putty (Debian:12) 0.63-1; putty (Debian:6.0) 0.60+2010-02-20-1+squeeze2.

Low priority for now. Upgrade to filezilla (Debian:12) 3.7.3-1; putty (Debian:12) 0.63-1; putty (Debian:6.0) 0.60+2010-02-20-1+squeeze2 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

The rsa_verify function in PuTTY before 0.63 (1) does not clear sensitive process memory after use and (2) does not free certain structures containing sensitive process memory, which might allow local users to discover private RSA and DSA keys.

LowCVSS 2.1 · v2.0—No exploit Fix available

Info leak

Published: Aug 19, 2013
Updated: Jun 16, 2026
EPSS: 0.4% · 31th percentile
CWE: CWE-200

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 8 / 40 · 2.1 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.4%

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
putty	putty	cpe:2.3:a:putty:putty
simon tatham	putty	cpe:2.3:a:simon_tatham:putty

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

putty putty0.45
putty putty0.46
putty putty0.47
putty putty0.48
putty putty0.49
putty putty0.50
putty putty0.51
putty putty0.52
putty putty0.53b
putty putty0.54
putty putty0.55
putty putty0.56
putty putty0.57
putty putty0.58
putty putty0.59
putty putty0.60
putty putty0.61
simon tatham puttyup to 0.62 inclusive
simon tatham putty0.53

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Debian:12	filezilla	before 3.7.3-1	3.7.3-1
Debian:12	putty	before 0.63-1	0.63-1
Debian:6.0	putty	before 0.60+2010-02-20-1+squeeze2	0.60+2010-02-20-1+squeeze2
Debian:7	putty	before 0.62-9+deb7u1	0.62-9+deb7u1
openSUSE:Tumbleweed	filezilla	before 3.23.0.2-1.1	3.23.0.2-1.1

Same product

putty: all records

Other highest-scoring records for the same primary product.

CVE-2017-6542The ssh_agent_channel_data function in PuTTY before 0.68 allows remote attackers to have unspecified impact via a large length value in an a
46Plan
CVE-2004-1008Integer signedness error in the ssh2_rdpkt function in PuTTY before 0.56 allows remote attackers to execute arbitrary code via a SSH2_MSG_DE
42Plan
CVE-2019-9898Potential recycling of random numbers used in cryptography exists within PuTTY before 0.71.
40Plan
CVE-2019-9895In PuTTY versions before 0.71 on Unix, a remotely triggerable buffer overflow exists in any kind of server-to-client forwarding.
40Plan
CVE-2019-17067PuTTY before 0.73 on Windows improperly opens port-forwarding listening sockets, which allows attackers to listen on the same port to steal
39Monitor
CVE-2021-36367PuTTY through 0.75 proceeds with establishing an SSH session even if it has never sent a substantive authentication response.
32Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
debian:filezilla	3.7.3-1 · Debian:12	Package registry (OSV)
debian:putty	0.63-1 · Debian:12	Package registry (OSV)
opensuse:filezilla	3.23.0.2-1.1 · openSUSE:Tumbleweed	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

No special conditions are required; it is repeatable.

If successful

Confidentiality: P · data can be read
Integrity: none
Availability: none

Attack complexity: Low
Confidentiality impact: P
Integrity impact: None
Availability impact: None

Weakness class (CWE)

CWE-200 · Exposure of Sensitive Information to an Unauthorized Actor

CVSS vector

AV:L/AC:L/Au:N/C:P/I:N/A:N

nvd-primary

Root cause

The extension requests broader permissions than its function needs and sends the data it collects out for purposes beyond its stated function.

The bug in code

The whole CWE-200 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

json

1{2  "permissions": ["tabs", "<all_urls>"],3  "background": { "service_worker": "analytics.js" }4}

Fixed

json

1{2  "permissions": ["activeTab"],3  "host_permissions": ["https://yildiz.example/*"]4}

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

ATT&CK techniques

Change log

Fix✗ → ✓Sep 28, 2026, 10:47 PM UTC

For records you follow, these changes also arrive as notifications. →

References

lists.opensuse.org/opensuse-updates/2013-08/msg00035.html

Show all references (5 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records