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Fencer Intel
medium 5.9

CVE-2013-2566 json

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…

published 13y ago modified 4mo ago also EUVD-2013-2508

cvss
5.9
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
84.4%
EPSS 84.4% chance of exploitation in 30 days, percentile 99.7%
public exploits
1
Metasploit

Summary

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 of ciphertext in a large number of sessions that use the same plaintext.

Patch / fix

  • mozilla firefox 17.0.11, 24.1.1, 25.0.1
  • mozilla seamonkey 2.22.1
  • mozilla thunderbird 24.1.1
  • mozilla thunderbird_esr 17.0.11
  • fujitsu sparc_enterprise_m3000_firmware xcp_1121
  • fujitsu sparc_enterprise_m4000_firmware xcp_1121
  • fujitsu sparc_enterprise_m5000_firmware xcp_1121
  • fujitsu sparc_enterprise_m8000_firmware xcp_1121
  • fujitsu sparc_enterprise_m9000_firmware xcp_1121
  • fujitsu m10-1_firmware xcp2280
  • fujitsu m10-4_firmware xcp2280
  • fujitsu m10-4s_firmware xcp2280

Is CVE-2013-2566 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2013-2566 updated cvss 4.3

SSL/TLS: Attack against RC4 stream cipher

  • Red Hat Enterprise Linux 5 nss, gnutls, openssl Red Hat Enterprise Linux 6 nss, gnutls, openssl, nss-tools, nss-sysinit, gnutls-guile, +2 more
    affected: no fix planned “Will not fix”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

cisa ICSA-21-075-02 updated cvss 7.5

GE UR Family (Update A)

  • GE Veronva UR B30 <8.10 GE Veronva UR B90 <8.10 GE Veronva UR C30 <8.10 GE Veronva UR C60 <8.10 GE Veronva UR C70 <8.10 GE Veronva UR C95 <8.10
    +13 more products
    GE Veronva UR D30 <8.10 GE Veronva UR D60 <8.10 GE Veronva UR F35 <8.10 GE Veronva UR F60 <8.10 GE Veronva UR G30 <8.10 GE Veronva UR G60 <8.10 GE Veronva UR L30 <8.10 GE Veronva UR L60 <8.10 GE Veronva UR L90 <8.10 GE Veronva UR M60 <8.10 GE Veronva UR N60 <8.10 GE Veronva UR T35 <8.10 GE Veronva UR T60 <8.10
    affected: vendor fix, mitigation “GE recommends users refer to the UR Deployment guide for secure configuration of UR IED and system.” gegridsolutions.com

From CISA ICS and IT advisories (CSAF, https://github.com/cisagov/CSAF), a U.S. Government work; changed: reduced to products, statuses and remediations. CISA notification · csaf

cisa ICSA-22-160-01 updated cvss 5.9

Mitsubishi Electric Air Conditioning Systems

  • Mitsubishi Electric AE-50A <= 7.97 Mitsubishi Electric AE-50E <= 7.97 Mitsubishi Electric AE-50J <= 7.97 Mitsubishi Electric AE-200A <= 7.97 Mitsubishi Electric AE-200E <= 7.97 Mitsubishi Electric AE-200J <= 7.97
    +14 more products
    Mitsubishi Electric AG-150A-A <= 3.21 Mitsubishi Electric AG-150A-J <= 3.21 Mitsubishi Electric EB-50GU-A <= 7.10 Mitsubishi Electric EB-50GU-J <= 7.10 Mitsubishi Electric EW-50A <= 7.97 Mitsubishi Electric EW-50E <= 7.97 Mitsubishi Electric EW-50J <= 7.97 Mitsubishi Electric G-150AD <= 3.21 Mitsubishi Electric GB-50AD <= 3.21 Mitsubishi Electric GB-50ADA-A <= 3.21 Mitsubishi Electric GB-50ADA-J <= 3.21 Mitsubishi Electric TE-50A <= 7.97 Mitsubishi Electric TE-200A <= 7.97 Mitsubishi Electric TW-50A <= 7.97
    affected: fixed in 7.98, mitigation “G-150AD: Replace the air conditioning systems to AE-200J, AE-50J or EW-50J Version 7.98 or later” mitsubishielectric.com

From CISA ICS and IT advisories (CSAF, https://github.com/cisagov/CSAF), a U.S. Government work; changed: reduced to products, statuses and remediations. CISA notification · csaf

Timeline

  1. Published
  2. First public exploit (Metasploit auxiliary/scanner/ssl/ssl_version)

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
5mo ago

Exploit prediction

84.42% chance of exploitation in the next 30 days, higher than 99.7% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

CVSS scores

assigned by version score vector
CISA ADP 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
CNA 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD 3.0 5.9 CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:P/I:N/A:N

Classification

Weakness
  • CWE-327 Use of a Broken or Risky Cryptographic Algorithm
  • CWE-326 Inadequate Encryption Strength

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.