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Fencer Intel
medium 6.5

CVE-2020-15693 json

In Nim 1.2.4, the standard library httpClient is vulnerable to a CR-LF injection in the target URL.

published 6y ago modified 4mo ago also EUVD-2020-7680

cvss
6.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.1%
EPSS 2.1% chance of exploitation in 30 days, percentile 82%
public exploits
0
none known

Summary

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.

Patch / fix

  • nim Debian 14, Debian 12 1.2.6-1

debian advisories DEBIAN-CVE-2020-15693

  • 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

Is CVE-2020-15693 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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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-2020-15693 updated cvss 6.5

nim: CR-LF injection in the target URL in standard library httpClient

  • 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

2.13% chance of exploitation in the next 30 days, higher than 82% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • openwall.com http://www.openwall.com/lists/oss-security/2021/02/04/2 referenced PoC, tagged "exploit" by a source, unverified
  • consensys.net https://consensys.net/diligence/vulnerabilities/nim-httpclient-header-crlf-injection/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
NVD 2.0 6.4 AV:N/AC:L/Au:N/C:P/I:P/A:N

Classification

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

References

Sources

Fencer Intel 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.