An issue was discovered in urllib2 in Python 2.x through 2.7.16 and urllib in Python 3.x through 3.7.3.
Noroxi assessment
Priority: Monitor (action score 26/100)
- 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: 5.4% (FIRST EPSS); higher than 92.6% of all records.
- Anyone who can reach it over the internet can trigger it. No account or password is required. A user must open a link or visit a page. No special conditions are required; it is repeatable.
- Fixed version: python-psycopg2-doc (AlmaLinux:8) 2.7.5-7.module_el8.6.0+2781+fed64c13; python2-attrs (AlmaLinux:8) 17.4.0-10.module_el8.6.0+2781+fed64c13; python2-chardet (AlmaLinux:8) 3.0.4-10.module_el8.6.0+2781+fed64c13.
- Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Low priority for now. Upgrade to python-psycopg2-doc (AlmaLinux:8) 2.7.5-7.module_el8.6.0+2781+fed64c13; python2-attrs (AlmaLinux:8) 17.4.0-10.module_el8.6.0+2781+fed64c13; python2-chardet (AlmaLinux:8) 3.0.4-10.module_el8.6.0+2781+fed64c13 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
An issue was discovered in urllib2 in Python 2.x through 2.7.16 and urllib in Python 3.x through 3.7.3. CRLF injection is possible if the attacker controls a url parameter, as demonstrated by the first argument to urllib.request.urlopen with \r\n (specifically in the query string after a ? character) followed by an HTTP header or a Redis command. This is fixed in: v2.7.17, v2.7.17rc1, v2.7.18, v2.7.18rc1; v3.5.10, v3.5.10rc1, v3.5.8, v3.5.8rc1, v3.5.8rc2, v3.5.9; v3.6.10, v3.6.10rc1, v3.6.11, v3.6.11rc1, v3.6.12, v3.6.9, v3.6.9rc1; v3.7.4, v3.7.4rc1, v3.7.4rc2, v3.7.5, v3.7.5rc1, v3.7.6, v3.7.6rc1, v3.7.7, v3.7.7rc1, v3.7.8, v3.7.8rc1, v3.7.9.
- BDU:2021-03607
- ALSA-2019:3335
- DLA-1834-1
- DLA-1835-1
- DLA-2280-1
- DLA-2337-1
- openSUSE-SU-2019:2131-1
- openSUSE-SU-2019:2133-1
- openSUSE-SU-2024:11204-1
- openSUSE-SU-2024:11277-1
- openSUSE-SU-2024:14055-1
- openSUSE-SU-2024:14128-1
- openSUSE-SU-2026:11378-1
- openSUSE-SU-2026:12044-1
- openSUSE-SU-2026:12045-1
- RHSA-2019:1260
- RHSA-2019:2030
- RHSA-2019:3335
- RHSA-2019:3520
- RHSA-2019:3725
- Published
- Mar 13, 2019
- Updated
- Oct 14, 2026
- EPSS
- 5.4% · 92th percentile
- CWE
- CWE-93
Report tools
Action score
26
Monitor
Low priority for now.
- CVSS
- 24 / 40 · 6.1 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 2 / 30 · 5.4%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 6.1
- CNA · mitre
- 6.5
- 0.4 point gap
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
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.
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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 helpAffected 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 |
|---|---|---|
| python | python | cpe:2.3:a:python:python |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- python python2.0 and later · before 2.7.17
- python python3.5.0 and later · before 3.5.8
- python python3.6.0 and later · before 3.6.9
- python python3.7.0 and later · before 3.7.4
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| AlmaLinux:8 | python-psycopg2-doc | before 2.7.5-7.module_el8.6.0+2781+fed64c13 | 2.7.5-7.module_el8.6.0+2781+fed64c13 |
| AlmaLinux:8 | python2-attrs | before 17.4.0-10.module_el8.6.0+2781+fed64c13 | 17.4.0-10.module_el8.6.0+2781+fed64c13 |
| AlmaLinux:8 | python2-chardet | before 3.0.4-10.module_el8.6.0+2781+fed64c13 | 3.0.4-10.module_el8.6.0+2781+fed64c13 |
| AlmaLinux:8 | python2-coverage | before 4.5.1-4.module_el8.6.0+2781+fed64c13 | 4.5.1-4.module_el8.6.0+2781+fed64c13 |
| AlmaLinux:8 | python2-Cython | before 0.28.1-7.module_el8.6.0+2781+fed64c13 | 0.28.1-7.module_el8.6.0+2781+fed64c13 |
| AlmaLinux:8 | python2-dns | before 1.15.0-10.module_el8.6.0+2781+fed64c13 | 1.15.0-10.module_el8.6.0+2781+fed64c13 |
| AlmaLinux:8 | python2-docs | before 2.7.16-2.module_el8.6.0+2781+fed64c13 | 2.7.16-2.module_el8.6.0+2781+fed64c13 |
| AlmaLinux:8 | python2-docs-info | before 2.7.16-2.module_el8.6.0+2781+fed64c13 | 2.7.16-2.module_el8.6.0+2781+fed64c13 |
| AlmaLinux:8 | python2-docutils | before 0.14-12.module_el8.6.0+2781+fed64c13 | 0.14-12.module_el8.6.0+2781+fed64c13 |
| AlmaLinux:8 | python2-funcsigs | before 1.0.2-13.module_el8.6.0+2781+fed64c13 | 1.0.2-13.module_el8.6.0+2781+fed64c13 |
| AlmaLinux:8 | python2-idna | before 2.5-7.module_el8.6.0+2781+fed64c13 | 2.5-7.module_el8.6.0+2781+fed64c13 |
| AlmaLinux:8 | python2-ipaddress | before 1.0.18-6.module_el8.6.0+2781+fed64c13 | 1.0.18-6.module_el8.6.0+2781+fed64c13 |
| AlmaLinux:8 | python2-markupsafe | before 0.23-19.module_el8.6.0+2781+fed64c13 | 0.23-19.module_el8.6.0+2781+fed64c13 |
| AlmaLinux:8 | python2-mock | before 2.0.0-13.module_el8.6.0+2781+fed64c13 | 2.0.0-13.module_el8.6.0+2781+fed64c13 |
| AlmaLinux:8 | python2-pluggy | before 0.6.0-8.module_el8.6.0+2781+fed64c13 | 0.6.0-8.module_el8.6.0+2781+fed64c13 |
| AlmaLinux:8 | python2-psycopg2 | before 2.7.5-7.module_el8.6.0+2781+fed64c13 | 2.7.5-7.module_el8.6.0+2781+fed64c13 |
| AlmaLinux:8 | python2-psycopg2-debug | before 2.7.5-7.module_el8.6.0+2781+fed64c13 | 2.7.5-7.module_el8.6.0+2781+fed64c13 |
| AlmaLinux:8 | python2-psycopg2-tests | before 2.7.5-7.module_el8.6.0+2781+fed64c13 | 2.7.5-7.module_el8.6.0+2781+fed64c13 |
| AlmaLinux:8 | python2-py | before 1.5.3-6.module_el8.6.0+2781+fed64c13 | 1.5.3-6.module_el8.6.0+2781+fed64c13 |
| AlmaLinux:8 | python2-PyMySQL | before 0.8.0-10.module_el8.6.0+2781+fed64c13 | 0.8.0-10.module_el8.6.0+2781+fed64c13 |
| AlmaLinux:8 | python2-pysocks | before 1.6.8-6.module_el8.6.0+2781+fed64c13 | 1.6.8-6.module_el8.6.0+2781+fed64c13 |
| AlmaLinux:8 | python2-pytest | before 3.4.2-13.module_el8.6.0+2781+fed64c13 | 3.4.2-13.module_el8.6.0+2781+fed64c13 |
| AlmaLinux:8 | python2-pytest-mock | before 1.9.0-4.module_el8.6.0+2781+fed64c13 | 1.9.0-4.module_el8.6.0+2781+fed64c13 |
| AlmaLinux:8 | python2-pytz | before 2017.2-12.module_el8.6.0+2781+fed64c13 | 2017.2-12.module_el8.6.0+2781+fed64c13 |
+96
Same product
python: all recordsOther highest-scoring records for the same primary product.
- CVE-2016-5636Integer overflow in the get_data function in zipimport.c in CPython (aka Python) before 2.7.12, 3.x before 3.4.5, and 3.5.x before 3.5.2 all47Plan
- CVE-2007-4559Directory traversal vulnerability in the (1) extract and (2) extractall functions in the tarfile module in Python allows user-assisted remot47Plan
- CVE-2021-3177Python 3.x through 3.9.1 has a buffer overflow in PyCArg_repr in _ctypes/callproc.c, which may lead to remote code execution in certain Pyth46Plan
Published before and after this one in the same product
- ← EarlierCVE-2018-20406Dec 23, 2018 · Modules/_pickle.c in Python before 3.7.1 has an integer overflow via a large LONG_BINPUT value that is mishandled during a "resize to twice 32Monitor
- ← EarlierCVE-2019-9636Mar 8, 2019 · Python 2.7.x through 2.7.16 and 3.x through 3.7.2 is affected by: Improper Handling of Unicode Encoding (with an incorrect netloc) during NF41Plan
- Later →CVE-2019-9947Mar 23, 2019 · An issue was discovered in urllib2 in Python 2.x through 2.7.16 and urllib in Python 3.x through 3.7.3.26Monitor
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 |
|---|---|---|
| almalinux:python-psycopg2-doc | 2.7.5-7.module_el8.6.0+2781+fed64c13 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:python2-attrs | 17.4.0-10.module_el8.6.0+2781+fed64c13 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:python2-chardet | 3.0.4-10.module_el8.6.0+2781+fed64c13 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:python2-coverage | 4.5.1-4.module_el8.6.0+2781+fed64c13 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:python2-Cython | 0.28.1-7.module_el8.6.0+2781+fed64c13 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:python2-dns | 1.15.0-10.module_el8.6.0+2781+fed64c13 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:python2-docs | 2.7.16-2.module_el8.6.0+2781+fed64c13 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:python2-docs-info | 2.7.16-2.module_el8.6.0+2781+fed64c13 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:python2-docutils | 0.14-12.module_el8.6.0+2781+fed64c13 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:python2-funcsigs | 1.0.2-13.module_el8.6.0+2781+fed64c13 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:python2-idna | 2.5-7.module_el8.6.0+2781+fed64c13 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:python2-PyMySQL | 0.8.0-10.module_el8.6.0+2781+fed64c13 · AlmaLinux:8 | Package registry (OSV) |
| debian:python2.7 | 2.7.16-3 · Debian:11 | Package registry (OSV) |
| debian:python3.4 | 3.4.2-1+deb8u3 · Debian:8 | Package registry (OSV) |
| debian:python3.5 | 3.5.3-1+deb9u2 · Debian:9 | Package registry (OSV) |
| opensuse:python-CherryPy | 18.6.1-1.2 · openSUSE:Tumbleweed | Package registry (OSV) |
| opensuse:python-urllib3 | 1.22-lp150.5.3.1 · openSUSE:Leap 15.0 | Package registry (OSV) |
| opensuse:python-urllib3_1 | 1.26.20-7.2 · openSUSE:Tumbleweed | Package registry (OSV) |
| opensuse:python-urllib3-test | 1.24-lp151.2.3.1 · openSUSE:Leap 15.1 | Package registry (OSV) |
| red hat:python | 0:2.7.5-86.el7 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:python-debuginfo | 0:2.7.5-86.el7 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:python-libs | 0:2.7.5-86.el7 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:python27-python | 0:2.7.16-4.el6 · Red Hat:rhel_software_collections:3::el6 | Package registry (OSV) |
| red hat:python27-python-debug | 0:2.7.16-4.el6 · Red Hat:rhel_software_collections:3::el6 | Package registry (OSV) |
| red hat:python27-python-debuginfo | 0:2.7.16-4.el6 · Red Hat:rhel_software_collections:3::el6 | Package registry (OSV) |
| red hat:python27-python-devel | 0:2.7.16-4.el6 · Red Hat:rhel_software_collections:3::el6 | Package registry (OSV) |
| red hat:python27-python-jinja2 | 0:2.6-12.el6 · Red Hat:rhel_software_collections:3::el6 | Package registry (OSV) |
| red hat:python27-python-libs | 0:2.7.16-4.el6 · Red Hat:rhel_software_collections:3::el6 | Package registry (OSV) |
| red hat:python27-python-test | 0:2.7.16-4.el6 · Red Hat:rhel_software_collections:3::el6 | Package registry (OSV) |
| red hat:python27-python-tools | 0:2.7.16-4.el6 · Red Hat:rhel_software_collections:3::el6 | Package registry (OSV) |
+25
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.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, 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-20-535 · Jul 16, 2020(Python için Güvenlik Güncellemeleri Yayınladı)
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- A user must open a link or visit a page.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- low · data can be read
- Integrity
- low · data or configuration can be modified
- Availability
- none
Impact can extend beyond the vulnerable component (scope changes).
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- Required
- Scope
- Changed
- Confidentiality impact
- Low
- Integrity impact
- Low
- Availability impact
- None
Weakness class (CWE)
CWE-93 · Improper Neutralization of CRLF Sequences ('CRLF Injection')CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
nvd-primary
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
- SSVC exploitation— → none
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (19 more)Show less
- lists.opensuse.org/opensuse-security-announce/2019-09/msg00041.html
- packetstormsecurity.com/files/154927/Slackware-Security-Advisory-python-Updates.html
- www.openwall.com/lists/oss-security/2021/02/04/2
- www.securityfocus.com/bid/107466
- access.redhat.com/errata/RHSA-2019:1260
- access.redhat.com/errata/RHSA-2019:2030
- access.redhat.com/errata/RHSA-2019:3335
- access.redhat.com/errata/RHSA-2019:3520
- access.redhat.com/errata/RHSA-2019:3725
- lists.debian.org/debian-lts-announce/2019/06/msg00022.html
- lists.debian.org/debian-lts-announce/2019/06/msg00023.html
- lists.debian.org/debian-lts-announce/2019/06/msg00026.html
- lists.debian.org/debian-lts-announce/2020/07/msg00011.html
- lists.debian.org/debian-lts-announce/2020/08/msg00034.html
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2ORNTF62QPLMJXIQ7KTZQ2776LMIXEKL/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/44TS66GJMO5H3RLMVZEBGEFTB6O2LJJU/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4X3HW5JRZ7GCPSR7UHJOLD7AWLTQCDVR/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JCPGLTTOBB3QEARDX4JOYURP6ELNNA2V/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JMWSKTNOHSUOT3L25QFJAVCFYZX46FYK/
Vendor advisories and official records. Exploit/PoC links are deliberately left out.