CVE-2016-2563

Exp

Stack-based buffer overflow in the SCP command-line utility in PuTTY before 0.67 and KiTTY 0.66.6.3 and earlier allows remote servers to cause a denial of service (stack memory corruption) or execute arbitrary code via a crafted SCP-SINK file-size response to an SCP download request.

Published: 2016-04-07 Last update: 2026-05-06 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2016-2563 is rated High Exploit Risk (85.9/100): CVSS Critical severity, with high exploitation likelihood (EPSS 26.59%, 96th percentile). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

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

Public exploit references (Exploit-DB) for CVE-2016-2563

EDB-ID Source Kind Published Link
39551 exploit_db edb 2016-03-10 Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2016-2563

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 2026-05-30 28.63% 26.59% -2.05%
2 2026-03-04 23.40% 28.63% +5.23%
3 2026-03-01 — 23.40% —

Full EPSS history (45 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2016-2563

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.0 CRITICAL
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]
7.5 2.0 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
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:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 6.4 [email protected]

Weakness enumeration for CVE-2016-2563

OS Trackers for CVE-2016-2563

vendor priority summary link
debian not yet assigned CVE-2016-2563 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-2016-2563
gentoo normal CVE-2016-2563: 1 GLSA(s) (201606-01), 1 atom(s) (net-misc/putty); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2016-2563
suse medium — https://www.suse.com/security/cve/CVE-2016-2563/
ubuntu medium CVE-2016-2563 medium priority: Ubuntu including 1 source packages (putty), 11 status rows across 11 suites (artful, bionic, cosmic, disco, precise, trusty, upstream, wily, xenial, yakkety, zesty): not-affected 7, ignored 2, DNE 1, released 1. https://ubuntu.com/security/CVE-2016-2563

Affected software / configurations for CVE-2016-2563

Vendor Product Version Raw CPE
9bis kitty <= 0.66.6.3 cpe:2.3:a:9bis:kitty:*:*:*:*:*:*:*:*
simon_tatham putty <= 0.66 cpe:2.3:a:simon_tatham:putty:*:*:*:*:*:*:*:*

References for CVE-2016-2563

cvelogic Threat Intelligence