Home/CVE/Nimble is a package manager for the Nim programming language. In Nim release versions before versions 1.2.10 and 1.4.4,
CVE
CVE-2021-213732
Nimble is a package manager for the Nim programming language. In Nim release versions before versions 1.2.10 and 1.4.4,
Nimble is a package manager for the Nim programming language. In Nim release versions before versions 1.2.10 and 1.4.4, "nimble refresh" fetches a list of Nimble packages over HTTPS by default. In case of error it falls back to a non-TLS URL http://irclogs.nim-lang.org/packages.json.
An attacker able to perform MitM can deliver a modified package list containing malicious software packages. If the packages are installed and used the attack escalates to untrusted code execution.
HIGH · CVSS 7.5
EPSS 0.01155
EPSS exploitation odds1.16% · top 37%
Act now
- Public exploit or PoC is available
- CVSS base score ≥ 7.0
No Sigma yet — build one →
YARA rules0
Look this up elsewhere - one-click external pivots
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How to read a CVE - triage first, then detect and patch
This page is every public fact about CVE-2021-21373, cross-linked. Its job is to answer one question fast - does this need my attention now? - and then hand you the two things you do about it. Here is how an analyst reads it.
Triage: should I act now? Four signals, and they are not interchangeable:
CVSSseverity - how bad it is IF exploited, 0-10. A high CVSS alone is not urgency; a flaw can be a perfect 10 and never actually be attacked.
EPSSprobability - a model’s estimate of the chance it is exploited in the next 30 days, 0-1. This is the “will it actually happen” signal.
CISA KEVconfirmed - it is being exploited in the wild right now. The strongest signal on the page; KEV beats any score.
Weaponisedavailability - public exploits / PoCs, and especially Metasploit modules rated Excellent / Great. Reliable, packaged exploit code means low-skill attackers can use it today.
How they combine: KEV, or a dependable Metasploit module, means patch now regardless of CVSS. High CVSS + low EPSS + no exploit is real but not an emergency - schedule it. Low CVSS but KEV-listed still gets patched now. The verdict above already weighed these for you; this is how it got there.
Then what - two workflows:
Detectwhen you cannot patch today, follow this CVE to the ATT&CK techniques it enables, then Build a SIEM detection (the green button) - author a rule, test it in Atomic, deploy it. That buys visibility while the patch waits.
PatchAffected products / packages tell you if you are exposed; Fixed versions by distribution and Vendor advisories give the exact version that closes it.
Reading order for the panels below: verdict + badges, then Public exploits / Metasploit (is it weaponised), then ATT&CK techniques + Sigma / IDS rules (can I detect it), then Affected products / packages + Fixed versions (am I exposed, what patches it), then Threat actors / IOCs (who uses it), then Scoring & timeline / references (the evidence).
EPSS exploitation probability
1.16%
Top 37%odds of exploitation in the next 30 days
CVSS metric silhouette
shape grows toward worst-case
SSVC triage
No SSVC vulnrichment for this CVE. CISA's Vulnrichment program scores newer CVEs (~2024 onwards) plus selected older critical ones. Use the EPSS probability + KEV status to triage instead.
CVSS vector breakdown
Exploitability - how they get in
Attack Vector
Network
Adjacent
Local
Physical
Attack Complexity
Low
High
Privileges Required
None
Low
High
User Interaction
None
Required
Scope
Unchanged
Changed
Impact - what breaks
Confidentiality
None
Low
High
Integrity
None
Low
High
Availability
None
Low
High
VECTOR
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:H/A:LLifecycle
- 26 Mar 2021Published to NVD
- 17 Jun 2026Last modified
Every entry is a recorded date - NVD publish/modify, CISA KEV add, public exploit disclosure. No inferred events.
Attack path
Full kill chain
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Public Exploits & PoCs
2These PoC and exploit links come from public sources and are not verified to be safe or functional. Review the code before running anything, and treat unverified entries as untrusted. Signed-in users mark whether it works, rate 1-10, and can report malware with a required reason that becomes a public comment.
Works?
no reports yet
Rating
Works?
no reports yet
Rating
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ATT&CK techniques
2Techniques this CVE enables. Pills with a solid outline are high confidence - named directly in ATT&CK or Nuclei, or human-curated by CTID; the rest are inferred from the weakness type using MITRE's CVE Mapping Methodology and the CWE → CAPEC chain. Broad, generic-weakness guesses are filtered out. A small N× marks a technique that N independent sources agree on.
▤ Build a SIEM detection for these techniques▤
CAPEC attack patterns
7Attack patterns this CVE enables - the bridge from weakness to ATT&CK technique.
CAPEC-CAPEC-141 · Cache Poisoning CAPEC-CAPEC-142 · DNS Cache Poisoning CAPEC-CAPEC-459 · Creating a Rogue Certification Authority Certificate CAPEC-CAPEC-475 · Signature Spoofing by Improper Validation CAPEC-CAPEC-73 · User-Controlled Filename CAPEC-CAPEC-76 · Manipulating Web Input to File System Calls CAPEC-CAPEC-85 · AJAX Footprinting
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Weakness Classification
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Affected Products & Versions
2nim-lang nim< 1.2.10
nim-lang nim>= 1.4.0 and < 1.4.4
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Related CVEs
8CVEs linked to this one by a shared weakness (CWE) or affected product - joins on data already in the engine, with the reason shown per row. Not a guess.
CVE-2002-0862
The (1) CertGetCertificateChain, (2) CertVerifyCertificateChainPolicy, and (3) W...
1
same CWE-295
CVE-2003-1229
X509TrustManager in (1) Java Secure Socket Extension (JSSE) in SDK and JRE 1.4.0...
same CWE-295
CVE-2005-3170
The LDAP client on Microsoft Windows 2000 before Update Rollup 1 for SP4 accepts...
same CWE-295
MEDIUM
CVE-2006-7246
NetworkManager 0.9.x does not pin a certificate's subject to an ESSID when 802.1...
same CWE-295
MEDIUM
CVE-2021-21374
Nimble is a package manager for the Nim programming language. In Nim release ver...
same CWE-348
HIGH
CVE-2022-31813
Apache HTTP Server 2.4.53 and earlier may not send the X-Forwarded-* headers to ...
same CWE-348
CRITICAL
CVE-2022-2255
A vulnerability was found in mod_wsgi. The X-Client-IP header is not removed fro...
same CWE-348
HIGH
CVE-2022-4537
The Hide My WP Ghost - Security Plugin plugin for WordPress is vulnerable to IP ...
same CWE-348
MEDIUM
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Vendor Advisories
5suse-csafopenSUSE-SU-2024:11093-1
suse-csafopenSUSE-SU-2022:10101-1
suse-csafopenSUSE-SU-2022:10095-1
suse-csafopenSUSE-SU-2021:0628-1
suse-csafopenSUSE-SU-2021:0618-1
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References & Sources
2Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.