How severe is CVE-2015-5309?

CVE-2015-5309 has a CVSS 2.0 base score of 4.3, rated medium severity.

Is CVE-2015-5309 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (88th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2015-5309?

CVE-2015-5309 primarily affects Simon Tatham Putty. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2015-5309?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2015-5309 published?

CVE-2015-5309 was published on 2015-12-07 and last updated on 2026-06-17.

CVE-2015-5309

CVE-2015-5309 is a medium-severity vulnerability in Simon Tatham Putty with a CVSS 2.0 base score of 4.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-189.

Key facts

Severity: Medium (CVSS 2.0 base score 4.3)
EPSS exploit prediction: 3% (88th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-189
Affected product: Simon Tatham Putty
Published: 2015-12-07
Last modified: 2026-06-17

Description

Integer overflow in the terminal emulator in PuTTY before 0.66 allows remote attackers to cause a denial of service (memory corruption) or possibly execute arbitrary code via an ECH (erase characters) escape sequence with a large parameter value, which triggers a buffer underflow.

Frequently asked questions

What is CVE-2015-5309?: Integer overflow in the terminal emulator in PuTTY before 0.66 allows remote attackers to cause a denial of service (memory corruption) or possibly execute arbitrary code via an ECH (erase characters) escape sequence with a large parameter value, which triggers a buffer underflow.
How severe is CVE-2015-5309?: CVE-2015-5309 has a CVSS 2.0 base score of 4.3, rated medium severity.
Is CVE-2015-5309 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (88th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2015-5309?: CVE-2015-5309 primarily affects Simon Tatham Putty. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2015-5309?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2015-5309 published?: CVE-2015-5309 was published on 2015-12-07 and last updated on 2026-06-17.

References

Affected products (4)

cpe:2.3:o:opensuse:leap:42.1:*:*:*:*:*:*:*
cpe:2.3:o:opensuse:opensuse:13.1:*:*:*:*:*:*:*
cpe:2.3:o:opensuse:opensuse:13.2:*:*:*:*:*:*:*
cpe:2.3:a:simon_tatham:putty:*:*:*:*:*:*:*:*

More vulnerabilities in Simon Tatham Putty

CVE-2016-2563 — Critical (CVSS 9.8): Stack-based buffer overflow in the SCP command-line utility in PuTTY before 0.67 and KiTTY 0.66.6.3 and earlier allows…
CVE-2013-4852 — Medium (CVSS 6.8): Integer overflow in PuTTY 0.62 and earlier, WinSCP before 5.1.6, and other products that use PuTTY allows remote SSH…
CVE-2013-4206 — Medium (CVSS 6.8): Heap-based buffer underflow in the modmul function in sshbn.c in PuTTY before 0.63 allows remote SSH servers to cause a…
CVE-2013-4207 — Medium (CVSS 4.3): Buffer overflow in sshbn.c in PuTTY before 0.63 allows remote SSH servers to cause a denial of service (crash) via an…
CVE-2015-2157 — Low (CVSS 2.1): The (1) ssh2_load_userkey and (2) ssh2_save_userkey functions in PuTTY 0.51 through 0.63 do not properly wipe SSH-2…
CVE-2013-4208 — Low (CVSS 2.1): The rsa_verify function in PuTTY before 0.63 (1) does not clear sensitive process memory after use and (2) does not…

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Other CWE-189 (Numeric Errors) vulnerabilities

CVE-2015-8396 — Critical (CVSS 10.0): Integer overflow in the ImageRegionReader::ReadIntoBuffer function in…
CVE-2015-7205 — Critical (CVSS 10.0): Integer underflow in the RTPReceiverVideo::ParseRtpPacket function in Mozilla Firefox before 43.0 and Firefox ESR 38.x…
CVE-2015-6575 — Critical (CVSS 10.0): SampleTable.cpp in libstagefright in Android before 5.1.1 LMY48I does not properly consider integer promotion, which…
CVE-2015-3864 — Critical (CVSS 10.0): Integer underflow in the MPEG4Extractor::parseChunk function in MPEG4Extractor.cpp in libstagefright in mediaserver in…
CVE-2015-3836 — Critical (CVSS 10.0): The Parse_wave function in arm-wt-22k/lib_src/eas_mdls.c in the Sonivox DLS-to-EAS converter in Android before 5.1.1…
CVE-2015-3834 — Critical (CVSS 10.0): Multiple integer overflows in the BnHDCP::onTransact function in media/libmedia/IHDCP.cpp in libstagefright in Android…

Browse all CWE-189 (Numeric Errors) vulnerabilities →