NVD / CVE Program· CNA GitHub_M

CVE-2022-21716: Buffer Overflow in Twisted

Noroxi assessment

Priority: Monitor (action score 31/100)

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: 3.5% (FIRST EPSS); higher than 89.1% of all records.
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
According to CISA the attack is automatable: targets can be found by mass scanning.
Fixed version: twisted (Debian:12) 22.2.0-1; twisted (Debian:9) 16.6.0-2+deb9u2; python-Twisted (openSUSE:Leap 15.3) 19.10.0-150200.3.12.1.
Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to twisted (Debian:12) 22.2.0-1; twisted (Debian:9) 16.6.0-2+deb9u2; python-Twisted (openSUSE:Leap 15.3) 19.10.0-150200.3.12.1 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

Twisted is an event-based framework for internet applications, supporting Python 3.6+. Prior to 22.2.0, Twisted SSH client and server implement is able to accept an infinite amount of data for the peer's SSH version identifier. This ends up with a buffer using all the available memory. The attach is a simple as `nc -rv localhost 22 < /dev/zero`. A patch is available in version 22.2.0. There are currently no known workarounds.

HighCVSS 7.5 · v3.1—No exploit Fix available

Published: Mar 3, 2022
Updated: Jun 17, 2026
EPSS: 3.5% · 89th percentile
CWE: CWE-120

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 30 / 40 · 7.5 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 1 / 30 · 3.5%

CISA SSVC decision

Exploitation: proof of concept
Automatable: yes
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: 7.5
CNA · GitHub_M: 7.5; agree

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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

If any of these changes, we'll tell you in the daily email digest.

Running WordPress? Scan your site free with WP Lens

Is your version affected? Check it

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.

We use this product, ask for help

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
twisted	twisted	cpe:2.3:a:twisted:twisted
debian	debian linux	cpe:2.3:o:debian:debian_linux
oracle	http server	cpe:2.3:a:oracle:http_server
oracle	zfs storage appliance kit	cpe:2.3:a:oracle:zfs_storage_appliance_kit
fedoraproject	fedora	cpe:2.3:o:fedoraproject:fedora

Affected versions

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

debian debian linux9.0
fedoraproject fedora35
fedoraproject fedora36
oracle http server12.2.1.3.0
oracle http server12.2.1.4.0
oracle zfs storage appliance kit8.8
twisted twisted21.7.0 and later · before 22.2.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

twisted twisted
- < 22.2.0affected

Package-level exposure

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

Ecosystem	Package	Affected range	Fix
Debian:12	twisted	before 22.2.0-1	22.2.0-1
Debian:9	twisted	before 16.6.0-2+deb9u2	16.6.0-2+deb9u2
openSUSE:Leap 15.3	python-Twisted	before 19.10.0-150200.3.12.1	19.10.0-150200.3.12.1
openSUSE:Leap 15.4	python-Twisted	before 22.2.0-150400.5.4.1	22.2.0-150400.5.4.1
openSUSE:Tumbleweed	python-Twisted	before 22.2.0-1.1	22.2.0-1.1
PyPI	twisted	from 21.7.0 · before 22.2.0	22.2.0
Red Hat:openstack:16.1::el8	python-twisted	before 0:16.4.1-19.el8ost	0:16.4.1-19.el8ost
Red Hat:openstack:16.1::el8	python-twisted-debugsource	before 0:16.4.1-19.el8ost	0:16.4.1-19.el8ost
Red Hat:openstack:16.1::el8	python3-twisted	before 0:16.4.1-19.el8ost	0:16.4.1-19.el8ost
Red Hat:openstack:16.1::el8	python3-twisted-debuginfo	before 0:16.4.1-19.el8ost	0:16.4.1-19.el8ost
SUSE:HPE Helion OpenStack 8	python-Twisted	before 15.2.1-9.17.1	15.2.1-9.17.1
SUSE:Linux Enterprise Module for Package Hub 15 SP3	python-Twisted	before 19.10.0-150200.3.12.1	19.10.0-150200.3.12.1
SUSE:Linux Enterprise Module for Server Applications 15 SP4	python-Twisted	before 22.2.0-150400.5.4.1	22.2.0-150400.5.4.1

Same product

twisted: all records

Other highest-scoring records for the same primary product.

CVE-2020-10109In Twisted Web through 19.10.0, there was an HTTP request splitting vulnerability.
40Plan
CVE-2020-10108In Twisted Web through 19.10.0, there was an HTTP request splitting vulnerability.
40Plan
CVE-2026-115775Twisted: Unauthenticated Remote Denial of Service in the Twisted words domish XML Element Stream via an Unbounded Element Tree
34Monitor

Published before and after this one in the same product

← EarlierCVE-2016-1000111Mar 11, 2020 · Twisted before 16.3.1 does not attempt to address RFC 3875 section 4.1.18 namespace conflicts and therefore does not protect CGI application
22Monitor
← EarlierCVE-2022-21712Feb 7, 2022 · Cookie and header exposure in twisted
30Monitor
Later →CVE-2022-24801Apr 4, 2022 · HTTP Request Smuggling in twisted.web
33Monitor

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:twisted	22.2.0-1 · Debian:12	Package registry (OSV)
opensuse:python-Twisted	19.10.0-150200.3.12.1 · openSUSE:Leap 15.3	Package registry (OSV)
PyPI:twisted	22.2.0	Package registry (OSV)
red hat:python-twisted	0:16.4.1-19.el8ost · Red Hat:openstack:16.1::el8	Package registry (OSV)
red hat:python-twisted-debugsource	0:16.4.1-19.el8ost · Red Hat:openstack:16.1::el8	Package registry (OSV)
red hat:python3-twisted	0:16.4.1-19.el8ost · Red Hat:openstack:16.1::el8	Package registry (OSV)
red hat:python3-twisted-debuginfo	0:16.4.1-19.el8ost · Red Hat:openstack:16.1::el8	Package registry (OSV)
suse:python-Twisted	19.10.0-150200.3.12.1 · SUSE:Linux Enterprise Module for Package Hub 15 SP3	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.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

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

twisted/twistedcommit 89c395e

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).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

TR-22-0247 · Mar 24, 2022(RedHat Güvenlik Güncellemesi)

All national notices →

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: none
Integrity: none
Availability: high · the service can be disrupted

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: None
Integrity impact: None
Availability impact: High

Weakness class (CWE)

CWE-120 · Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

nvd-primary

Root cause

When data is copied, the source length is not compared with the size of the destination buffer. Excess data overwrites adjacent memory.

The bug in code

The whole CWE-120 class

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

Vulnerable

1char buf[256];
2memcpy(buf, pkt->data, pkt->len);

Fixed

1char buf[256];
2if (pkt->len > sizeof(buf)) {
3  return -EINVAL;
4}
5memcpy(buf, pkt->data, pkt->len);

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, 10:46 PM UTC

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

References

github.com/twisted/twisted/commit/89c395ee794e85a9657b112c4351417850330ef9

Show all references (7 more)

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

All records