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
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.
- EPSS probability
- 84.42% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 99.6% 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 10:41Z5 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
- Data version
- 5.2
- Document digest
- edf8cd7d5a3d15f1d130187ab96b7694bba97d4fafb55cf49ad1430b950b9f3c
05 Affected products
VendorProductVersionsPlatforms
06 References
- www.oracle.comhttp://www.oracle.com/technetwork/security-advisory/cpujan2018-3236628.html
- blog.cryptographyengineering.comhttp://blog.cryptographyengineering.com/2013/03/attack-of-week-rc4-is-kind-of-broken-in.html
- www.securityfocus.com58796http://www.securityfocus.com/bid/58796
- www.oracle.comhttp://www.oracle.com/technetwork/security-advisory/cpujul2016-2881720.html
- cr.yp.tohttp://cr.yp.to/talks/2013.03.12/slides.pdf
- marc.infoHPSBGN03324http://marc.info/?l=bugtraq&m=143039468003789&w=2
- www.oracle.comhttp://www.oracle.com/technetwork/security-advisory/cpuoct2016-2881722.html
- security.gentoo.orgGLSA-201504-01https://security.gentoo.org/glsa/201504-01
- security.gentoo.orgGLSA-201406-19http://security.gentoo.org/glsa/glsa-201406-19.xml
- www.oracle.comhttp://www.oracle.com/technetwork/security-advisory/cpuoct2017-3236626.html
- www.ubuntu.comUSN-2031-1http://www.ubuntu.com/usn/USN-2031-1
- www.ubuntu.comUSN-2032-1http://www.ubuntu.com/usn/USN-2032-1
- my.opera.comhttp://my.opera.com/securitygroup/blog/2013/03/20/on-the-precariousness-of-rc4
- www.oracle.comhttp://www.oracle.com/technetwork/security-advisory/cpuapr2016v3-2985753.html
- www.opera.comhttp://www.opera.com/security/advisory/1046
- kb.juniper.nethttp://kb.juniper.net/InfoCenter/index?page=content&id=JSA10705
- h20566.www2.hpe.comhttps://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05336888
- www.mozilla.orghttp://www.mozilla.org/security/announce/2013/mfsa2013-103.html
- www.isg.rhul.ac.ukhttp://www.isg.rhul.ac.uk/tls/
- www.opera.comhttp://www.opera.com/docs/changelogs/unified/1215/
- h20566.www2.hpe.comhttps://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05289935