CVE-2009-4257

CVE-2009-4257 is a critical-severity vulnerability in Realnetworks Realplayer with a CVSS 2.0 base score of 9.3. 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-119.

Key facts

• Severity: Critical (CVSS 2.0 base score 9.3)
• EPSS exploit prediction: 9% (94th percentile)
• Actively exploited: Not listed in CISA KEV
• Weakness: CWE-119
• Affected product: Realnetworks Realplayer
• Published: 2010-01-25
• Last modified: 2026-06-16

Description

Heap-based buffer overflow in datatype/smil/common/smlpkt.cpp in smlrender.dll in RealNetworks RealPlayer 10, RealPlayer 10.5 6.0.12.1040 through 6.0.12.1741, RealPlayer 11 11.0.0 through 11.0.4, RealPlayer Enterprise, Mac RealPlayer 10 and 10.1, Linux RealPlayer 10 and 11.0.0, and Helix Player 10.x and 11.0.0 allows remote attackers to execute arbitrary code via an SMIL file with crafted string lengths.

Frequently asked questions

What is CVE-2009-4257?

Heap-based buffer overflow in datatype/smil/common/smlpkt.cpp in smlrender.dll in RealNetworks RealPlayer 10, RealPlayer 10.5 6.0.12.1040 through 6.0.12.1741, RealPlayer 11 11.0.0 through 11.0.4, RealPlayer Enterprise, Mac RealPlayer 10 and 10.1, Linux RealPlayer 10 and 11.0.0, and Helix Player 10.x and 11.0.0 allows remote attackers to execute arbitrary code via an SMIL file with crafted string lengths.

How severe is CVE-2009-4257?

CVE-2009-4257 has a CVSS 2.0 base score of 9.3, rated critical severity.

Is CVE-2009-4257 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 9% (94th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2009-4257?

CVE-2009-4257 primarily affects Realnetworks Realplayer. In total, 18 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2009-4257?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2009-4257 published?

CVE-2009-4257 was published on 2010-01-25 and last updated on 2026-06-16.

References

• http://lists.helixcommunity.org/pipermail/datatype-cvs/2008-September/008678.html
• http://secunia.com/advisories/38218
• http://secunia.com/advisories/38450
• http://securitytracker.com/id?1023489
• http://service.real.com/realplayer/security/01192010_player/en/
• http://www.redhat.com/support/errata/RHSA-2010-0094.html
• http://www.securityfocus.com/archive/1/509105/100/0/threaded
• http://www.securityfocus.com/bid/37880
• http://www.vupen.com/english/advisories/2010/0178
• http://www.zerodayinitiative.com/advisories/ZDI-10-007/
• https://bugzilla.redhat.com/show_bug.cgi?id=561309
• https://exchange.xforce.ibmcloud.com/vulnerabilities/55798
• https://helixcommunity.org/viewcvs/datatype/smil/common/smlpkt.cpp?view=log#rev1.12
• https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A11110

Affected products (18)

• cpe:2.3:a:realnetworks:realplayer:10.0:*:*:*:*:*:*:*
• cpe:2.3:a:realnetworks:realplayer:10.5:*:*:*:*:*:*:*
• cpe:2.3:a:realnetworks:realplayer:11.0:*:*:*:*:*:*:*
• cpe:2.3:a:realnetworks:realplayer:11.0.1:*:*:*:*:*:*:*
• cpe:2.3:a:realnetworks:realplayer:11.0.2:*:*:*:*:*:*:*
• cpe:2.3:a:realnetworks:realplayer:11.0.3:*:*:*:*:*:*:*
• cpe:2.3:a:realnetworks:realplayer:11.0.4:*:*:*:*:*:*:*
• cpe:2.3:a:realnetworks:realplayer:11.0.5:*:*:*:*:*:*:*
• cpe:2.3:a:realnetworks:realplayer_enterprise:*:*:*:*:*:*:*:*
• cpe:2.3:a:realnetworks:realplayer_sp:1.0.0:*:*:*:*:*:*:*
• cpe:2.3:a:realnetworks:realplayer_sp:1.0.1:*:*:*:*:*:*:*
• cpe:2.3:a:realnetworks:realplayer:10.1:*:*:*:*:*:*:*
• cpe:2.3:a:realnetworks:helix_player:10.0:*:*:*:*:*:*:*
• cpe:2.3:a:realnetworks:helix_player:11.0.0:*:*:*:*:*:*:*
• cpe:2.3:a:realnetworks:helix_player:11.0.1:*:*:*:*:*:*:*
• cpe:2.3:a:realnetworks:realplayer:10.0:*:linux:*:*:*:*:*
• cpe:2.3:a:realnetworks:realplayer:11.0.0:*:linux:*:*:*:*:*
• cpe:2.3:a:realnetworks:realplayer:11.0.1:*:linux:*:*:*:*:*

More vulnerabilities in Realnetworks Realplayer

• CVE-2011-4256 — Critical (CVSS 10.0): The RV30 codec in RealNetworks RealPlayer before 15.0.0 and Mac RealPlayer before 12.0.0.1703 does not initialize an…
• CVE-2011-4255 — Critical (CVSS 10.0): Unspecified vulnerability in RealNetworks RealPlayer before 15.0.0 and Mac RealPlayer before 12.0.0.1703 allows remote…
• CVE-2011-4254 — Critical (CVSS 10.0): RealNetworks RealPlayer before 15.0.0 allows remote attackers to execute arbitrary code via a crafted RTSP SETUP…
• CVE-2011-4253 — Critical (CVSS 10.0): Unspecified vulnerability in the RV20 codec in RealNetworks RealPlayer before 15.0.0 and Mac RealPlayer before…
• CVE-2011-4250 — Critical (CVSS 10.0): Unspecified vulnerability in the ATRC codec in RealNetworks RealPlayer before 15.0.0 and Mac RealPlayer before…
• CVE-2011-4249 — Critical (CVSS 10.0): Array index error in the RV30 codec in RealNetworks RealPlayer before 15.0.0 allows remote attackers to execute…

All CVEs affecting Realnetworks Realplayer →

Other CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) vulnerabilities

• CVE-2026-2778 — Critical (CVSS 10.0): Sandbox escape due to incorrect boundary conditions in the DOM: Core & HTML component. This vulnerability was fixed in…
• CVE-2026-2776 — Critical (CVSS 10.0): Sandbox escape due to incorrect boundary conditions in the Telemetry component in External Software. This vulnerability…
• CVE-2025-1866 — Critical (CVSS 10.0): Improper Restriction of Operations within the Bounds of a Memory Buffer vulnerability in warmcat libwebsockets allows…
• CVE-2022-27625 — Critical (CVSS 10.0): A vulnerability regarding improper restriction of operations within the bounds of a memory buffer is found in the…
• CVE-2022-27624 — Critical (CVSS 10.0): A vulnerability regarding improper restriction of operations within the bounds of a memory buffer is found in the…
• CVE-2020-11896 — Critical (CVSS 10.0): The Treck TCP/IP stack before 6.0.1.66 allows Remote Code Execution, related to IPv4 tunneling.

Browse all CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) vulnerabilities →