01 Record

CVE-2013-2566

The RC4 algorithm, as used in the TLS protocol and SSL protocol, has many single-byte biases, which makes it easier for remote attackers to conduct plaintext-recovery attacks via statistical analysis

MediumPUBLISHEDCNA: mitre

CNA base score5.9 CVSS v3.xCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

View raw JSON

02 Description

The RC4 algorithm, as used in the TLS protocol and SSL protocol, has many single-byte biases, which makes it easier for remote attackers to conduct plaintext-recovery attacks via statistical analysis

03 Exploitation and scoring

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

84.42% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 99.7% of scored records. A rank, not a probability.

NVD base score

5.9 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

NVD analysis status

Modified. NVD last modified this record on 2026-06-16.

Red Hat severity

Moderate. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published

2013-03-14 22:00Z13 YR AGO

Last updated

2026-05-22 10:41Z3 MO AGO

Reserved

2013-03-14

Assigning CNA

mitre

Record state

PUBLISHED

Severity

Medium (CVSS 5.9)

CNA CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Weaknesses

CWE-327Use of a Broken or Risky Cryptographic AlgorithmClass
CWE-326Inadequate Encryption StrengthClass

Data version

5.2

Document digest

edf8cd7d5a3d15f1d130187ab96b7694bba97d4fafb55cf49ad1430b950b9f3c

05 Affected products

VendorProductVersionsPlatforms

canonicalubuntu_linuxNot specified—

fujitsum10-1Not specified—

fujitsum10-1_firmwareNot specified—

fujitsum10-4Not specified—

fujitsum10-4_firmwareNot specified—

fujitsum10-4sNot specified—

fujitsum10-4s_firmwareNot specified—

fujitsusparc_enterprise_m3000Not specified—

fujitsusparc_enterprise_m3000_firmwareNot specified—

fujitsusparc_enterprise_m4000Not specified—

fujitsusparc_enterprise_m4000_firmwareNot specified—

fujitsusparc_enterprise_m5000Not specified—

fujitsusparc_enterprise_m5000_firmwareNot specified—

fujitsusparc_enterprise_m8000Not specified—

fujitsusparc_enterprise_m8000_firmwareNot specified—

fujitsusparc_enterprise_m9000Not specified—

fujitsusparc_enterprise_m9000_firmwareNot specified—

mozillafirefoxNot specified—

mozillaseamonkeyNot specified—

mozillathunderbirdNot specified—

mozillathunderbird_esrNot specified—

oraclecommunications_application_session_controllerNot specified—

oraclehttp_serverNot specified—

oracleintegrated_lights_out_manager_firmwareNot specified—

redhatenterprise_linuxNot specified—

06 References

www.oracle.comhttp://www.oracle.com/technetwork/security-advisory/cpujan2018-3236628.htmlx_refsource_CONFIRM
blog.cryptographyengineering.comhttp://blog.cryptographyengineering.com/2013/03/attack-of-week-rc4-is-kind-of-broken-in.htmlx_refsource_MISC
www.securityfocus.com58796http://www.securityfocus.com/bid/58796vdb-entryx_refsource_BID
www.oracle.comhttp://www.oracle.com/technetwork/security-advisory/cpujul2016-2881720.htmlx_refsource_CONFIRM
cr.yp.tohttp://cr.yp.to/talks/2013.03.12/slides.pdfx_refsource_MISC
marc.infoHPSBGN03324http://marc.info/?l=bugtraq&m=143039468003789&w=2vendor-advisoryx_refsource_HP
www.oracle.comhttp://www.oracle.com/technetwork/security-advisory/cpuoct2016-2881722.htmlx_refsource_CONFIRM
security.gentoo.orgGLSA-201504-01https://security.gentoo.org/glsa/201504-01vendor-advisoryx_refsource_GENTOO
security.gentoo.orgGLSA-201406-19http://security.gentoo.org/glsa/glsa-201406-19.xmlvendor-advisoryx_refsource_GENTOO
www.oracle.comhttp://www.oracle.com/technetwork/security-advisory/cpuoct2017-3236626.htmlx_refsource_CONFIRM
www.ubuntu.comUSN-2031-1http://www.ubuntu.com/usn/USN-2031-1vendor-advisoryx_refsource_UBUNTU
www.ubuntu.comUSN-2032-1http://www.ubuntu.com/usn/USN-2032-1vendor-advisoryx_refsource_UBUNTU
my.opera.comhttp://my.opera.com/securitygroup/blog/2013/03/20/on-the-precariousness-of-rc4x_refsource_CONFIRM
www.oracle.comhttp://www.oracle.com/technetwork/security-advisory/cpuapr2016v3-2985753.htmlx_refsource_CONFIRM
www.opera.comhttp://www.opera.com/security/advisory/1046x_refsource_CONFIRM
kb.juniper.nethttp://kb.juniper.net/InfoCenter/index?page=content&id=JSA10705x_refsource_CONFIRM
h20566.www2.hpe.comhttps://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05336888x_refsource_CONFIRM
www.mozilla.orghttp://www.mozilla.org/security/announce/2013/mfsa2013-103.htmlx_refsource_CONFIRM
www.isg.rhul.ac.ukhttp://www.isg.rhul.ac.uk/tls/x_refsource_MISC
www.opera.comhttp://www.opera.com/docs/changelogs/unified/1215/x_refsource_CONFIRM
h20566.www2.hpe.comhttps://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05289935x_refsource_CONFIRM

01 Record index

CVE-2013-2566

02 Description

03 Exploitation and scoring

04 Metadata

05 Affected products

06 References

02 Records

CVE-2013-2566

02 Description

03 Exploitation and scoring

04 Metadata

05 Affected products

06 References