CVE-2015-2157

The (1) ssh2_load_userkey and (2) ssh2_save_userkey functions in PuTTY 0.51 through 0.63 do not properly wipe SSH-2 private keys from memory, which allows local users to obtain sensitive information by reading the memory.

Published: 2015-03-27 Last update: 2026-05-06 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2015-2157 is rated Low Risk (17/100): CVSS Low severity, with low exploitation likelihood (EPSS 0.09%). Mandatory action: Low composite risk—no urgent action required; patch on your normal maintenance cycle and revisit priority if CVSS or EPSS increases.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2015-2157

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-03-01 0.27% 0.09% -0.18%
2 2026-02-04 0.09% 0.27% +0.18%
3 2026-02-01 0.09%

Full EPSS history (30 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2015-2157

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
2.1 2.0 LOW
AV:L/AC:L/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
3.9 2.9 [email protected]

Weakness enumeration for CVE-2015-2157

OS Trackers for CVE-2015-2157

vendor priority summary link
debian not yet assigned CVE-2015-2157 not yet assigned priority: Debian including 1 source packages (putty), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2015-2157
ubuntu low CVE-2015-2157 low priority: Ubuntu including 1 source packages (putty), 10 status rows across 10 suites (lucid, precise, trusty, upstream, utopic, vivid, wily, xenial, yakkety, zesty): not-affected 5, released 3, ignored 2. https://ubuntu.com/security/CVE-2015-2157

Affected software / configurations for CVE-2015-2157

Vendor Product Version Raw CPE
debian debian_linux 7.0 cpe:2.3:o:debian:debian_linux:7.0:*:*:*:*:*:*:*
fedoraproject fedora 20 cpe:2.3:o:fedoraproject:fedora:20:*:*:*:*:*:*:*
fedoraproject fedora 22 cpe:2.3:o:fedoraproject:fedora:22:*:*:*:*:*:*:*
opensuse opensuse 13.1 cpe:2.3:o:opensuse:opensuse:13.1:*:*:*:*:*:*:*
opensuse opensuse 13.2 cpe:2.3:o:opensuse:opensuse:13.2:*:*:*:*:*:*:*
putty putty 0.51 cpe:2.3:a:putty:putty:0.51:*:*:*:*:*:*:*
putty putty 0.52 cpe:2.3:a:putty:putty:0.52:*:*:*:*:*:*:*
putty putty 0.53b cpe:2.3:a:putty:putty:0.53b:*:*:*:*:*:*:*
putty putty 0.54 cpe:2.3:a:putty:putty:0.54:*:*:*:*:*:*:*
putty putty 0.55 cpe:2.3:a:putty:putty:0.55:*:*:*:*:*:*:*
putty putty 0.56 cpe:2.3:a:putty:putty:0.56:*:*:*:*:*:*:*
putty putty 0.57 cpe:2.3:a:putty:putty:0.57:*:*:*:*:*:*:*
putty putty 0.58 cpe:2.3:a:putty:putty:0.58:*:*:*:*:*:*:*
putty putty 0.59 cpe:2.3:a:putty:putty:0.59:*:*:*:*:*:*:*
putty putty 0.60 cpe:2.3:a:putty:putty:0.60:*:*:*:*:*:*:*
putty putty 0.61 cpe:2.3:a:putty:putty:0.61:*:*:*:*:*:*:*
putty putty 0.62 cpe:2.3:a:putty:putty:0.62:*:*:*:*:*:*:*
putty putty 0.63 cpe:2.3:a:putty:putty:0.63:*:*:*:*:*:*:*
simon_tatham putty 0.53 cpe:2.3:a:simon_tatham:putty:0.53:*:*:*:*:*:*:*

References for CVE-2015-2157

cvelogic Threat Intelligence