CVE-2020-5202
apt-cacher-ng through 3.3 allows local users to obtain sensitive information by hijacking the...
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.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
5.5
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.
- Record
CVE-2020-5202- CVSS 3.1
- 5.5 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N - CVSS 2.0
- 2.1 Low
AV:L/AC:L/Au:N/C:P/I:N/A:N - Updated
- 2026-11-02
CVE List No score
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.
- Record
CVE-2020-5202- Updated
- 2026-11-02
EUVDEUVD-2020-26446 No score
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.
- Record
EUVD-2020-26446- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-ppjv-mwcc-539j No score
apt-cacher-ng through 3.3 allows local users to obtain sensitive information by hijacking the...
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.
- Record
GHSA-ppjv-mwcc-539j- Weakness
- CWE-200
- Updated
- 2026-11-02
OSV
5.5
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.
- Record
CVE-2020-5202- CVSS 3.1
- 5.5 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
OSVDEBIAN-CVE-2020-5202
5.5
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.
- Record
DEBIAN-CVE-2020-5202- CVSS 3.1
- 5.5 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
OSVUBUNTU-CVE-2020-5202
5.5
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.
- Record
UBUNTU-CVE-2020-5202- CVSS 3.1
- 5.5 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
OSVopenSUSE-SU-2020:0124-1 No score
Security update for apt-cacher-ng
This update for apt-cacher-ng fixes the following issues:
- CVE-2019-18899: Fixed a symlink attack which could allow to overwrite arbitrary data (boo#1157703).
- CVE-2020-5202: Fixed an information leak if a local user won a race condition to listen to localhost:3142 (boo#1157706).
- Record
openSUSE-SU-2020:0124-1- Updated
- 2026-11-02
OSVopenSUSE-SU-2020:0146-1 No score
Security update for apt-cacher-ng
This update for apt-cacher-ng fixes the following issues:
- CVE-2019-18899: Fixed a symlink attack which could allow to overwrite arbitrary data (boo#1157703).
- CVE-2020-5202: Fixed an information leak if a local user won a race condition to listen to localhost:3142 (boo#1157706).
This update was imported from the openSUSE:Leap:15.1:Update update project.
- Record
openSUSE-SU-2020:0146-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
apt-cacher-ngDebian:12 |
before 3.3.1-1 | 3.3.1-1 |
apt-cacher-ngDebian:13 |
before 3.3.1-1 | 3.3.1-1 |
apt-cacher-ngDebian:14 |
before 3.3.1-1 | 3.3.1-1 |
apt-cacher-ngUbuntu:16.04:LTS |
All versions, plus listed versions 0.8.5-10.8.6-10.8.7-10.8.8-10.8.9-10.8.9-1ubuntu10.9.1-1ubuntu1 |
None known |
apt-cacher-ngUbuntu:18.04:LTS |
All versions, plus listed versions 3-53.1-13.1-1build1 |
None known |
apt-cacher-ngopenSUSE:Leap 15.1 From an advisory covering 2 CVEs |
before 3.1-lp151.3.3.1 | 3.1-lp151.3.3.1 |
apt-cacher-ngSUSE:Package Hub 15 SP1 From an advisory covering 2 CVEs |
before 3.1-bp151.4.3.1 | 3.1-bp151.4.3.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-5202 is a medium vulnerability (CVSS 5.5) in Apt-cacher-ng Project Apt-cacher-ng, published January 21, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.47%, the 40th percentile. Fixed in apt-cacher-ng 3.3.1-1.
References
security-tracker.debian.org/tracker/CVE-2020-5202
openwall.com/lists/oss-security/2020/01/20/4
seclists.org/oss-sec/2020/q1/21
lists.opensuse.org/opensuse-security-announce/2020-01/msg00057.html
lists.opensuse.org/opensuse-security-announce/2020-01/msg00065.html
nvd.nist.gov/vuln/detail/CVE-2020-5202
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github.com/advisories/GHSA-ppjv-mwcc-539j
ubuntu.com/security/CVE-2020-5202
cve.org/CVERecord?id=CVE-2020-5202
lists.opensuse.org/archives/list/[email protected]/thread/L5YHDY4KQ2XQQ6FVEBGPECNI4RJRU3NR
bugzilla.suse.com/1157703
bugzilla.suse.com/1157706
suse.com/security/cve/CVE-2019-18899
suse.com/security/cve/CVE-2020-5202
lists.opensuse.org/archives/list/[email protected]/thread/WNHKIYENNBZYQZDAXUMNWHSYC2SN5WOD