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CVE-2018-20969· NVD / CVE Program· CNA mitre

do_ed_script in pch.c in GNU patch through 2.7.6 does not block strings beginning with a ! character.

do_ed_script in pch.c in GNU patch through 2.7.6 does not block strings beginning with a ! character. NOTE: this is the same commit as for CVE-2019-13638, but the ! syntax is specific to ed, and is unrelated to a shell metacharacter.

HighCVSS 7.8 · v3.0—No exploit Fix available
Published
Aug 16, 2019
Updated
Jun 16, 2026
EPSS
2.7% · 85th percentile
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Report tools

JSON

Action score

32

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
1 / 30 · 2.7%

Affected systems

VendorProduct
gnupatch

Affected versions

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

  • gnu patchup to 2.7.6 inclusive

Package-level exposure

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

EcosystemPackageAffected rangeFix
Alpine:v3.10patchbefore 2.7.6-r62.7.6-r6
Debian:10patchbefore 2.7.6-3+deb10u12.7.6-3+deb10u1
Debian:12patchbefore 2.7.6-52.7.6-5
Debian:8patchbefore 2.7.5-1+deb8u32.7.5-1+deb8u3
Debian:9patchbefore 2.7.5-1+deb9u22.7.5-1+deb9u2
Red Hat:enterprise_linux:7::clientpatchbefore 0:2.7.1-12.el7_70:2.7.1-12.el7_7
Red Hat:enterprise_linux:7::clientpatch-debuginfobefore 0:2.7.1-12.el7_70:2.7.1-12.el7_7
Red Hat:enterprise_linux:8::baseospatchbefore 0:2.7.6-9.el8_00:2.7.6-9.el8_0
Red Hat:enterprise_linux:8::baseospatch-debuginfobefore 0:2.7.6-9.el8_00:2.7.6-9.el8_0
Red Hat:enterprise_linux:8::baseospatch-debugsourcebefore 0:2.7.6-9.el8_00:2.7.6-9.el8_0
Red Hat:rhel_aus:7.4::serverpatchbefore 0:2.7.1-11.el7_40:2.7.1-11.el7_4
Red Hat:rhel_aus:7.4::serverpatch-debuginfobefore 0:2.7.1-11.el7_40:2.7.1-11.el7_4
Red Hat:rhel_eus:7.5::computenodepatchbefore 0:2.7.1-11.el7_50:2.7.1-11.el7_5
Red Hat:rhel_eus:7.5::computenodepatch-debuginfobefore 0:2.7.1-11.el7_50:2.7.1-11.el7_5
Red Hat:rhel_eus:7.6::computenodepatchbefore 0:2.7.1-11.el7_60:2.7.1-11.el7_6
Red Hat:rhel_eus:7.6::computenodepatch-debuginfobefore 0:2.7.1-11.el7_60:2.7.1-11.el7_6

Same product

gnu: all records

Other highest-scoring records for the same primary product.

  • CVE-2018-1000156GNU Patch version 2.7.6 contains an input validation vulnerability when processing patch files, specifically the EDITOR_PROGRAM invocation (
    33Monitor
  • CVE-2018-6951An issue was discovered in GNU patch through 2.7.6.
    33Monitor
  • CVE-2015-1395Directory traversal vulnerability in GNU patch versions which support Git-style patching before 2.7.3 allows remote attackers to write to ar
    33Monitor
  • CVE-2019-13638GNU patch through 2.7.6 is vulnerable to OS shell command injection that can be exploited by opening a crafted patch file that contains an e
    32Monitor
  • CVE-2018-6952A double free exists in the another_hunk function in pch.c in GNU patch through 2.7.6.
    32Monitor
  • CVE-2015-1396A Directory Traversal vulnerability exists in the GNU patch before 2.7.4.
    31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
alpine:patch2.7.6-r6 · Alpine:v3.10Package registry (OSV)
debian:patch2.7.6-5 · Debian:12Package registry (OSV)
red hat:patch0:2.7.6-9.el8_0 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:patch-debuginfo0:2.7.6-9.el8_0 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:patch-debugsource0:2.7.6-9.el8_0 · Red Hat:enterprise_linux:8::baseosPackage 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.

EPSS, last 120 days

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.

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).

Technical details

Attack conditions

  • Someone with local access to the system 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
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-78 · Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

CVSS vector

CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

nvd-primary

Root cause

User input is inserted as text into a shell command. The shell may interpret special characters in the input as part of the command.

The bug in code

The whole CWE-78 class

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

Vulnerable

ts
const host = req.body.host;exec("ping -c 1 " + host, onResult);

Fixed

ts
const host = req.body.host;if (!/^[a-z0-9.-]{1,253}$/i.test(host)) return res.sendStatus(400);execFile("ping", ["-c", "1", host], onResult);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Noroxi analysis

No Noroxi analysis for this record yet

We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.

We use this product, ask for help

Change log

  1. Fix✗ → ✓

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References

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

All records