In Nim 1.2.4, the standard library httpClient is vulnerable to a CR-LF injection in the target URL.
Noroxi assessment
Priority: Monitor (action score 27/100)
- 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: 2.1% (FIRST EPSS); higher than 81.4% 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.
- Fixed version: nim (Debian:12) 1.2.6-1; nim (openSUSE:Tumbleweed) 1.6.6-3.1; nim (SUSE:Package Hub 15 SP3) 1.6.6-bp153.2.3.1.
Low priority for now. Upgrade to nim (Debian:12) 1.2.6-1; nim (openSUSE:Tumbleweed) 1.6.6-3.1; nim (SUSE:Package Hub 15 SP3) 1.6.6-bp153.2.3.1 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
In Nim 1.2.4, the standard library httpClient is vulnerable to a CR-LF injection in the target URL. An injection is possible if the attacker controls any part of the URL provided in a call (such as httpClient.get or httpClient.post), the User-Agent header value, or custom HTTP header names or values.
- Published
- Aug 14, 2020
- Updated
- Jun 16, 2026
- EPSS
- 2.1% · 81th percentile
- CWE
- CWE-74
Report tools
Action score
27
Monitor
Low priority for now.
- CVSS
- 26 / 40 · 6.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 1 / 30 · 2.1%
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 |
|---|---|---|
| nim-lang | nim | cpe:2.3:a:nim-lang:nim |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- nim-lang nimup to 1.2.6 inclusive
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | nim | before 1.2.6-1 | 1.2.6-1 |
| openSUSE:Tumbleweed | nim | before 1.6.6-3.1 | 1.6.6-3.1 |
| SUSE:Package Hub 15 SP3 | nim | before 1.6.6-bp153.2.3.1 | 1.6.6-bp153.2.3.1 |
| SUSE:Package Hub 15 SP3 | nim | before 1.6.6-bp153.2.3.1 | 1.6.6-bp153.2.3.1 |
| SUSE:Package Hub 15 SP4 | nim | before 1.6.6-bp154.2.3.1 | 1.6.6-bp154.2.3.1 |
| SUSE:Package Hub 15 SP4 | nim | before 1.6.6-bp154.2.3.1 | 1.6.6-bp154.2.3.1 |
Same product
nim-lang: all recordsOther highest-scoring records for the same primary product.
- CVE-2020-15690In Nim before 1.2.6, the standard library asyncftpclient lacks a check for whether a message contains a newline character.40Plan
- CVE-2020-15692In Nim 1.2.4, the standard library browsers mishandles the URL argument to browsers.openDefaultBrowser.40Plan
- CVE-2021-21372Nimble arbitrary code execution for specially crafted package metadata36Monitor
- CVE-2021-21374Nimble fails to validate certificates due to insecure httpClient defaults32Monitor
- CVE-2020-15694In Nim 1.2.4, the standard library httpClient fails to properly validate the server response.31Monitor
- CVE-2021-29495Nim stdlib httpClient does not validate peer certificates by default30Monitor
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:nim | 1.2.6-1 · Debian:12 | Package registry (OSV) |
| opensuse:nim | 1.6.6-bp153.2.3.1 · openSUSE:Leap 15.3 | Package registry (OSV) |
| suse:nim | 1.6.6-bp153.2.3.1 · SUSE: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.
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).
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
- low · data can be read
- Integrity
- low · data or configuration can be modified
- Availability
- none
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- Low
- Integrity impact
- Low
- Availability impact
- None
Weakness class (CWE)
CWE-74 · Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/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)
- Buffer Overflow via Environment VariablesCAPEC-10likelihood: High · High
- Server Side Include (SSI) InjectionCAPEC-101likelihood: High · High
- HTTP Request SplittingCAPEC-105likelihood: Medium · High
- Command Line Execution through SQL InjectionCAPEC-108likelihood: Low · Very High
- Double EncodingCAPEC-120likelihood: Low · Medium
- Subverting Environment Variable ValuesCAPEC-13likelihood: High · Very High
- Format String InjectionCAPEC-135likelihood: High · High
- Client-side Injection-induced Buffer OverflowCAPEC-14likelihood: Medium · High
Change log
- Fix✗ → ✓
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References
Show all references (1 more)Show less
Vendor advisories and official records. Exploit/PoC links are deliberately left out.