CVE-2020-16135

Exp

libssh 0.9.4 has a NULL pointer dereference in tftpserver.c if ssh_buffer_new returns NULL.

Published: 2020-07-29 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-16135 is rated High Exploit Risk (72.6/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 4.11%). 1 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +2.70% over the last day, indicating growing attacker interest. 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-2020-16135

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2020-16135

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 2026-06-15 1.41% 4.11% +2.70%
2 2026-04-17 1.78% 1.41% -0.38%
3 2026-01-31 — 1.78% —

Full EPSS history (32 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-16135

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.9 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/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:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
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:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.2 3.6 [email protected]
4.3 2.0 MEDIUM
AV:N/AC:M/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.6 2.9 [email protected]

Weakness enumeration for CVE-2020-16135

OS Trackers for CVE-2020-16135

vendor priority summary link
alpine medium CVE-2020-16135: 1 source package rows (libssh); 11 state rows across 9 repos (3.10-main, 3.11-main, 3.17-community, 3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 9, open 2. https://security.alpinelinux.org/vuln/CVE-2020-16135
debian not yet assigned CVE-2020-16135 not yet assigned priority: Debian including 1 source packages (libssh), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2020-16135
gentoo normal CVE-2020-16135: 1 GLSA(s) (202011-05), 1 atom(s) (net-libs/libssh); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2020-16135
redhat low — https://access.redhat.com/security/cve/CVE-2020-16135
suse medium CVE-2020-16135 severity moderate: SUSE including 278 source package names (13.2-3.8.1:libssh-config-0.9.8-150200.13.3.1, 13.2-3.8.1:libssh4-0.9.8-150200.13.3.1, …), 465 product×package rows across 81 product lines (Container suse/ltss/sle12.5/sles12sp5, Container suse/sle-micro-rancher/5.2, … (81 product lines)): Known Affected 225, Fixed 186, Known Not Affected 54. https://www.suse.com/security/cve/CVE-2020-16135/
ubuntu medium CVE-2020-16135 medium priority: Ubuntu including 1 source packages (libssh), 5 status rows across 5 suites (bionic, focal, trusty, upstream, xenial): released 3, DNE 1, needs-triage 1. https://ubuntu.com/security/CVE-2020-16135

Affected software / configurations for CVE-2020-16135

Vendor Product Version Raw CPE
libssh libssh 0.9.4 cpe:2.3:a:libssh:libssh:0.9.4:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
fedoraproject fedora 32 cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
fedoraproject fedora 33 cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
canonical ubuntu_linux 16.04 cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:*
canonical ubuntu_linux 18.04 cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 20.04 cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:*
oracle communications_cloud_native_core_policy 1.15.0 cpe:2.3:a:oracle:communications_cloud_native_core_policy:1.15.0:*:*:*:*:*:*:*

References for CVE-2020-16135

URL Tags
https://bugs.libssh.org/T232 Issue Tracking Vendor Advisory
https://bugs.libssh.org/rLIBSSHe631ebb3e2247dd25e9678e6827c20dc73b73238 Exploit Issue Tracking Vendor Advisory
https://gitlab.com/libssh/libssh-mirror/-/merge_requests/120 Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/07/msg00034.html Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FCIKQRKXAAB4HMWM62EPZJ4DVBHIIEG6/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JNW5GBC6JFN76VEWQXMLT5F7VCZ5AJ2E/
https://security.gentoo.org/glsa/202011-05 Third Party Advisory
https://usn.ubuntu.com/4447-1/ Third Party Advisory
https://www.oracle.com/security-alerts/cpuapr2022.html Patch Third Party Advisory
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