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Fencer Intel
medium 5.5

CVE-2020-5202 json

apt-cacher-ng through 3.3 allows local users to obtain sensitive information by hijacking the hardcoded TCP port.

published 6y ago modified 4mo ago also EUVD-2020-26446

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 40%
public exploits
0
none known

Summary

apt-cacher-ng through 3.3 allows local users to obtain sensitive information by hijacking the hardcoded TCP port. The /usr/lib/apt-cacher-ng/acngtool program attempts to connect to apt-cacher-ng via TCP on localhost port 3142, even if the explicit SocketPath=/var/run/apt-cacher-ng/socket command-line option is passed. The cron job /etc/cron.daily/apt-cacher-ng (which is active by default) attempts this periodically. Because 3142 is an unprivileged port, any local user can try to bind to this port and will receive requests from acngtool. There can be sensitive data in these requests, e.g., if AdminAuth is enabled in /etc/apt-cacher-ng/security.conf. This sensitive data can leak to unprivileged local users that manage to bind to this port before the apt-cacher-ng daemon can.

Patch / fix

  • apt-cacher-ng Debian 14, Debian 13, Debian 12 3.3.1-1

debian advisories DEBIAN-CVE-2020-5202

  • apt-cacher-ng Package Hub 15 SP1 3.1-bp151.4.3.1
  • apt-cacher-ng openSUSE Leap 15.1 3.1-lp151.3.3.1

opensuse advisories openSUSE-SU-2020:0146-1openSUSE-SU-2020:0124-1

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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-2020-5202 updated cvss 5.5

apt-cacher-ng: local unprivileged user can impersonate the apt-cacher-ng daemon leading to credentials leak

  • 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

0.47% chance of exploitation in the next 30 days, higher than 40% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • openwall.com http://www.openwall.com/lists/oss-security/2020/01/20/4 referenced PoC, tagged "exploit" by a source, unverified
  • seclists.org https://seclists.org/oss-sec/2020/q1/21 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
NVD 2.0 2.1 AV:L/AC:L/Au:N/C:P/I:N/A:N

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.