How severe is CVE-2010-4020?

CVE-2010-4020 has a CVSS 3.x base score of 6.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.

Is CVE-2010-4020 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (77th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2010-4020?

CVE-2010-4020 primarily affects Mit Kerberos 5. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2010-4020?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2010-4020 published?

CVE-2010-4020 was published on 2010-12-02 and last updated on 2026-06-16.

CVE-2010-4020

CVE-2010-4020 is a medium-severity vulnerability in Mit Kerberos 5 with a CVSS 3.x base score of 6.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-310.

Key facts

Severity: Medium (CVSS 3.x base score 6.3)
CVSS v2: 3.5
EPSS exploit prediction: 2% (77th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-310
Affected product: Mit Kerberos 5
Published: 2010-12-02
Last modified: 2026-06-16

Description

MIT Kerberos 5 (aka krb5) 1.8.x through 1.8.3 does not reject RC4 key-derivation checksums, which might allow remote authenticated users to forge a (1) AD-SIGNEDPATH or (2) AD-KDC-ISSUED signature, and possibly gain privileges, by leveraging the small key space that results from certain one-byte stream-cipher operations.

Frequently asked questions

What is CVE-2010-4020?: MIT Kerberos 5 (aka krb5) 1.8.x through 1.8.3 does not reject RC4 key-derivation checksums, which might allow remote authenticated users to forge a (1) AD-SIGNEDPATH or (2) AD-KDC-ISSUED signature, and possibly gain privileges, by leveraging the small key space that results from certain one-byte stream-cipher operations.
How severe is CVE-2010-4020?: CVE-2010-4020 has a CVSS 3.x base score of 6.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2010-4020 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (77th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2010-4020?: CVE-2010-4020 primarily affects Mit Kerberos 5. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2010-4020?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2010-4020 published?: CVE-2010-4020 was published on 2010-12-02 and last updated on 2026-06-16.

References

Affected products (4)

cpe:2.3:a:mit:kerberos_5:1.8:*:*:*:*:*:*:*
cpe:2.3:a:mit:kerberos_5:1.8.1:*:*:*:*:*:*:*
cpe:2.3:a:mit:kerberos_5:1.8.2:*:*:*:*:*:*:*
cpe:2.3:a:mit:kerberos_5:1.8.3:*:*:*:*:*:*:*

More vulnerabilities in Mit Kerberos 5

CVE-2011-0285 — Critical (CVSS 10.0): The process_chpw_request function in schpw.c in the password-changing functionality in kadmind in MIT Kerberos 5 (aka…
CVE-2009-4212 — Critical (CVSS 10.0): Multiple integer underflows in the (1) AES and (2) RC4 decryption functionality in the crypto library in MIT Kerberos 5…
CVE-2009-0846 — Critical (CVSS 10.0): The asn1_decode_generaltime function in lib/krb5/asn.1/asn1_decode.c in the ASN.1 GeneralizedTime decoder in MIT…
CVE-2008-0947 — Critical (CVSS 10.0): Buffer overflow in the RPC library used by libgssrpc and kadmind in MIT Kerberos 5 (krb5) 1.4 through 1.6.3 allows…
CVE-2007-5902 — Critical (CVSS 10.0): Integer overflow in the svcauth_gss_get_principal function in lib/rpc/svc_auth_gss.c in MIT Kerberos 5 (krb5) allows…
CVE-2007-4743 — Critical (CVSS 10.0): The original patch for CVE-2007-3999 in svc_auth_gss.c in the RPCSEC_GSS RPC library in MIT Kerberos 5 (krb5) 1.4…

All CVEs affecting Mit Kerberos 5 →

Other CWE-310 (Cryptographic Issues) vulnerabilities

CVE-2014-7878 — Critical (CVSS 10.0): The Application Lifecycle Service (ALS) in HP Helion Cloud Development Platform 1.0, when a virtual machine is derived…
CVE-2013-3712 — Critical (CVSS 10.0): SUSE Studio Onsite 1.3.x before 1.3.6 and SUSE Studio Extension for System z 1.3 uses "static" secret tokens, which has…
CVE-2013-6952 — Critical (CVSS 10.0): The Belkin WeMo Home Automation firmware before 3949 has a hardcoded GPG key, which makes it easier for remote…
CVE-2013-6838 — Critical (CVSS 10.0): An unspecified Enghouse Interactive Professional Services "addon product" in Enghouse Interactive IVR Pro (VIP2000)…
CVE-2013-0137 — Critical (CVSS 10.0): The default configuration of the Digital Alert Systems DASDEC EAS device before 2.0-2 and the Monroe Electronics R189…
CVE-2011-5123 — Critical (CVSS 10.0): The Antivirus component in Comodo Internet Security before 5.3.175888.1227 does not check whether X.509 certificates in…

Browse all CWE-310 (Cryptographic Issues) vulnerabilities →