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Fencer Vulns
critical 9.8

CVE-2020-15690 json

In Nim before 1.2.6, the standard library asyncftpclient lacks a check for whether a message contains a newline character.

published 2021-01-30 5 y ago modified 2026-06-17 4 mo ago also EUVD-2020-7677

cvss
9.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
3.2%
EPSS 3.2% chance of exploitation in 30 days, percentile 88%
public exploits
0
none known

Summary

In Nim before 1.2.6, the standard library asyncftpclient lacks a check for whether a message contains a newline character.

Patch / fix

  • nim-lang nim 1.2.6
  • nim Debian 14, Debian 12 1.2.6-1

debian advisories DEBIAN-CVE-2020-15690

  • nim openSUSE Tumbleweed 1.6.6-3.1
  • nim Package Hub 15 SP4, openSUSE Leap 15.4 1.6.6-bp154.2.3.1
  • nim Package Hub 15 SP3, openSUSE Leap 15.3 1.6.6-bp153.2.3.1

opensuse advisories openSUSE-SU-2024:12253-1openSUSE-SU-2022:10101-1openSUSE-SU-2022:10095-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2020-15690 updated

nim: Standard library asyncftpclient lacks a check for newline character

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

3.22% chance of exploitation in the next 30 days, higher than 88% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/nim-lang/Nim/blob/dc5a40f3f39c6ea672e6dc6aca7f8118a69dda99/lib/pure/asyncftpclient.nim#L145 referenced PoC, tagged "exploit" by a source, unverified
  • consensys.net https://consensys.net/diligence/vulnerabilities/nim-asyncftpd-crlf-injection/ referenced PoC, tagged "exploit" by a source, unverified
  • github.com https://github.com/tintinweb/pub/tree/master/pocs/cve-2020-15690 referenced PoC, tagged "exploit" by a source, unverified
  • openwall.com http://www.openwall.com/lists/oss-security/2021/02/04/3 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P

Classification

Weakness
  • CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.