synced 11 MIN AGO
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.
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
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
  • 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—
oraclehttp_serverNot specified—
redhatenterprise_linuxNot specified—

06 References