In GNU Less before 609, crafted data can result in "less -R" not filtering ANSI escape sequences sent to the terminal.
- Published
- Feb 7, 2023
- Updated
- Jun 17, 2026
- EPSS
- 1.4% · 72th percentile
- CWE
- —
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Report tools
Action score
30
Monitor
Low priority for now.
- CVSS
- 30 / 40 · 7.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 1.4%
CISA SSVC decision
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| gnu | less | cpe:2.3:a:gnu:less |
| 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.
- fedoraproject fedora37
- gnu less566 and later · before 609
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| AlmaLinux:9 | less | before 590-2.el9_2 | 590-2.el9_2 |
| Debian:12 | less | before 590-1.2 | 590-1.2 |
| openSUSE:Tumbleweed | less | before 608-2.1 | 608-2.1 |
| Red Hat:enterprise_linux:9::baseos | less | before 0:590-2.el9_2 | 0:590-2.el9_2 |
| Red Hat:enterprise_linux:9::baseos | less-debuginfo | before 0:590-2.el9_2 | 0:590-2.el9_2 |
| Red Hat:enterprise_linux:9::baseos | less-debugsource | before 0:590-2.el9_2 | 0:590-2.el9_2 |
| Rocky Linux:9 | less | before 0:590-2.el9_2 | 0:590-2.el9_2 |
| SUSE:Linux Enterprise Micro 5.3 | less | before 590-150400.3.3.1 | 590-150400.3.3.1 |
| SUSE:Linux Enterprise Micro 5.3 | less | before 590-150400.3.3.1 | 590-150400.3.3.1 |
Same product
gnu: all recordsOther highest-scoring records for the same primary product.
- CVE-2014-9488The is_utf8_well_formed function in GNU less before 475 allows remote attackers to have unspecified impact via malformed UTF-8 characters, w41Plan
- CVE-2004-2264Format string bug in the open_altfile function in filename.c for GNU less 382, 381, and 358 might allow local users to cause a denial of ser26Monitor
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:less | 590-2.el9_2 · AlmaLinux:9 | Package registry (OSV) |
| debian:less | 590-1.2 · Debian:12 | Package registry (OSV) |
| opensuse:less | 590-150400.3.3.1 · openSUSE:Leap Micro 5.3 | Package registry (OSV) |
| red hat:less | 0:590-2.el9_2 · Red Hat:enterprise_linux:9::baseos | Package registry (OSV) |
| red hat:less-debuginfo | 0:590-2.el9_2 · Red Hat:enterprise_linux:9::baseos | Package registry (OSV) |
| red hat:less-debugsource | 0:590-2.el9_2 · Red Hat:enterprise_linux:9::baseos | Package registry (OSV) |
| rocky linux:less | 0:590-2.el9_2 · Rocky Linux:9 | Package registry (OSV) |
| suse:less | 590-150400.3.3.1 · SUSE:Linux Enterprise Micro 5.3 | 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.
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 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).
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)
—
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
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 helpChange log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- www.greenwoodsoftware.com/less/news.609.html
- www.openwall.com/lists/oss-security/2023/02/07/7
- github.com/gwsw/less/commit/a78e1351113cef564d790a730d657a321624d79c
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LR7AUWB34JD4PCW3HHASBEDGGHFWPAQP/
- security.gentoo.org/glsa/202310-11
- www.openwall.com/lists/oss-security/2023/02/07/7
Vendor advisories and official records. Exploit/PoC links are deliberately left out.