CVE Intelligence
Medium Cryptography

CVE-2011-3389 — Inadequate Encryption Strength in Canonical Ubuntu Linux

The SSL protocol, as used in certain configurations in Microsoft Windows and Microsoft Internet Explorer, Mozilla Firefox, Google Chrome, Opera, and other products, encrypts data by using CBC mode with chained initialization vectors, which allows man-in-the-middle attackers to obtain plaintext HTTP headers via a blockwise chosen-boundary attack (BCBA) on an HTTPS session, in conjunction with JavaScript code that uses (1) the HTML5 WebSocket API, (2) the Java URLConnection API, or (3) the Silverlight WebClient API, aka a "BEAST" attack.

Published Sep 6, 2011 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: mitre

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

Metasploit modules · 1
How the score was calculated
  • Public exploit/PoC (metasploit)+12
  • EPSS 73.3% (30-day exploitation probability)+15
  • Technical severity (medium)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
73.33%
ahead of 99% of scored CVEs · Oct 14, 2026
Affects
Canonical
Ubuntu Linux and 14 more
CVSS base
4.3
Medium · 1 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
None
none · proof-of-concept · active
Automatable
No
can an attacker script the kill-chain steps
Technical impact
Partial
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Canonical Ubuntu Linux, Debian Debian Linux, Google Chrome…).
  2. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  3. Apply the fixed version or the patch documented under Remediation.
  4. EPSS ahead of 99% of scored CVEs: prioritize it in the patch queue.
  5. Search available logs for exploit probes matching the vulnerability class (cryptography), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Canonical Ubuntu Linux version 10.04version 10.10version 11.04version 11.10 Vulnerable NIST National Vulnerability Database
Debian Debian Linux version 6.0version 5.0 Vulnerable NIST National Vulnerability Database
Google Chrome versions not specified by the source Vulnerable NIST National Vulnerability Database
Haxx Curl ≥ 7.10.6 and ≤ 7.23.1 Vulnerable NIST National Vulnerability Database
Microsoft Internet Explorer versions not specified by the source Vulnerable NIST National Vulnerability Database
Microsoft Windows versions not specified by the source Vulnerable NIST National Vulnerability Database
Mozilla Firefox versions not specified by the source Vulnerable NIST National Vulnerability Database
Opera Opera Browser versions not specified by the source Vulnerable NIST National Vulnerability Database
Red Hat Enterprise Linux Desktop version 6.0version 5.0 Vulnerable NIST National Vulnerability Database
Red Hat Enterprise Linux Eus version 6.2 Vulnerable NIST National Vulnerability Database
Red Hat Enterprise Linux Server version 5.0version 6.0 Vulnerable NIST National Vulnerability Database
Red Hat Enterprise Linux Server Aus version 6.2 Vulnerable NIST National Vulnerability Database
Red Hat Enterprise Linux Workstation version 5.0version 6.0 Vulnerable NIST National Vulnerability Database
Siemens Simatic Rf615r Firmware < 3.2.1 Vulnerable NIST National Vulnerability Database
Siemens Simatic Rf68xr Firmware < 3.2.1 Vulnerable NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Network
Attack complexity
Medium
Authentication
None
Confidentiality
Partial
Integrity
None
Availability
None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
4.3 CVSS 2.0 Medium 8.6 2.9 nvd@nist.gov via NIST National Vulnerability Database
AV:N/AC:M/Au:N/C:P/I:N/A:N (score shown at the top: nvd@nist.gov)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-326 · Inadequate Encryption Strength

Other CVEs with this weakness →

Public exploits, PoCs and detection templates

Public code that demonstrates or tests the flaw raises the odds of mass exploitation — and Nuclei templates help find vulnerable assets in your environment.

Metasploit modules

Warning: public PoCs are sometimes disguised malware. Use them only for authorized testing in an isolated environment. This portal does not host exploit code — it only points to the sources.

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 73.33%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
  • Check TLS negotiations and unexpected certificates in the component’s traffic.
web/proxy/WAF logsnetwork IDS/IPS

Timeline

What happened to this CVE, newest first.

  • 2026
  • SSVC assessment updated
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 13, 2026
  • Fix documented
    Oct 13, 2026 · NIST National Vulnerability Database
  • CVSS changed · 4.3
    Oct 13, 2026 · NIST National Vulnerability Database
  • Source status changed · → Modified
    Oct 13, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 13, 2026 · NIST National Vulnerability Database
  • 2011
  • CVE published
    Sep 6, 2011 · mitre

Source activity

Repeated readings are counted rather than listed.

  • 1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

89 on the record

Elsewhere on this site

Canonical
every CVE for this vendor
Cryptography
same class
CWE-326
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-110172 Use after free in Media in Google Chrome prior to 155.0.8059.79 allowed a remote attacker to... 1d
  • CVE-2026-110170 Use after free in Bindings in Google Chrome prior to 155.0.8059.79 allowed a remote attacker to... 1d
  • CVE-2026-110171 Use after free in Media in Google Chrome prior to 155.0.8059.79 allowed a remote attacker to... 1d
  • CVE-2026-110166 Buffer overflow in Animation in Google Chrome prior to 155.0.8059.79 allowed a remote attacker to... 1d
  • CVE-2026-110164 Use after free in DOM in Google Chrome prior to 155.0.8059.79 allowed a remote attacker to... 1d
  • CVE-2026-110165 Use after free in Core in Google Chrome on on Android prior to 155.0.8059.79 allowed a remote... 1d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2011-3389 is "Inadequate Encryption Strength in Canonical Ubuntu Linux", rated Medium. It affects Ubuntu Linux (Canonical); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 4.3 describes technical severity. EPSS 73.33% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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