CVE-2011-3634: methods/https.cc in apt before 0.8.11 accepts connections when the certificate host name fails validation and

Q: How do I fix CVE-2011-3634?

advanced package tool: upgrade to newer than 0.8.10.3; ubuntu linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Q: Is CVE-2011-3634 being exploited?

CVE-2011-3634 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2011-3634 affect?

CVE-2011-3634 affects advanced package tool, ubuntu linux. Severity is low (CVSS 2.6). methods/https.cc in apt before 0.8.11 accepts connections when the certificate host name fails validation and Verify-Host is enabled, which allows man-in-the-middle attackers to obtain repository credentials via unspecified vectors.

Q: How urgent is CVE-2011-3634?

Priority 28/100. On your watchlist

Routine

LOW 2.6WATCHLISTUPGRADEMITIGATE

CVE-2011-3634 is a low-severity flaw (CVSS 2.6) affecting advanced package tool, ubuntu linux. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

methods/https.cc in apt before 0.8.11 accepts connections when the certificate host name fails validation and Verify-Host is enabled, which allows man-in-the-middle attackers to obtain repository credentials via unspecified vectors.

Why this priority

On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	2.6 (Low)
EPSS exploit chance	0.8% (top 43%)
CISA exploited list	No
Weakness	CWE-200
Published	2014-03-01
Last modified	2026-06-16

Publisher (CNA): Red Hat, Inc. · Vendor: canonical · debian

Last updated 2026-06-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2014-03-01 00:55 UTCPublished CVE record published
2026-06-16 23:33 UTCUpdated Record last modified

debian advanced package tool UPGRADE

Affected: <= 0.8.10.3 · 0.8.0 · 0.8.0 pre1 · 0.8.0 pre2 · 0.8.1 · 0.8.10 · 0.8.10.1 · 0.8.10.2

Fixed in: newer than 0.8.10.3

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy advanced-package-tool || rpm -q advanced-package-tool || advanced-package-tool --version

2. UPGRADE to newer than 0.8.10.3 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade advanced-package-tool

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade advanced-package-tool

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

canonical ubuntu linux MITIGATE

Affected: 8.04 · 10.04 · 10.10 · 11.04

Fixed in: no fixed release known

Safe to downgrade to: a release before 8.04

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2011-3634?

advanced package tool: upgrade to newer than 0.8.10.3; ubuntu linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2011-3634 being exploited?

CVE-2011-3634 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2011-3634 affect?

CVE-2011-3634 affects advanced package tool, ubuntu linux. Severity is low (CVSS 2.6). methods/https.cc in apt before 0.8.11 accepts connections when the certificate host name fails validation and Verify-Host is enabled, which allows man-in-the-middle attackers to obtain repository credentials via unspecified vectors.

How urgent is CVE-2011-3634?

Priority 28/100. On your watchlist

Software pages

Ubuntu vulnerabilities · Debian vulnerabilities

Related CVEs

CVE-2020-27351 LOW 2.0 MITIGATE Various memory and file descriptor leaks were found in apt-python files python/arfile.cc, python/tag.cc, pytho
CVE-2020-27350 MEDIUM 5.7 UPGRADE MITIGATE APT had several integer overflows and underflows while parsing .deb packages, aka GHSL-2020-168 GHSL-2020-169,
CVE-2019-3462 HIGH 8.1 UPGRADE MITIGATE Incorrect sanitation of the 302 redirect field in HTTP transport method of apt versions 1.4.8 and earlier can
CVE-2018-0501 MEDIUM 5.9 MITIGATE UPGRADE The mirror:// method implementation in Advanced Package Tool (APT) 1.6.x before 1.6.4 and 1.7.x before 1.7.0~a
CVE-2016-1252 MEDIUM 5.9 UPGRADE MITIGATE The apt package in Debian jessie before 1.0.9.8.4, in Debian unstable before 1.4~beta2, in Ubuntu 14.04 LTS be

References

← Back to latest CVEs