CVE-2021-43311
CVE-2021-43311 is a high-severity vulnerability in Upx with a CVSS 3.x base score of 7.5. 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-787.
Key facts
- Severity: High (CVSS 3.x base score 7.5)
- EPSS exploit prediction: 1% (53rd percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-787
- Affected product: Upx
- Published:
- Last modified:
Description
A heap-based buffer overflow was discovered in upx, during the generic pointer 'p' points to an inaccessible address in func get_le32(). The problem is essentially caused in PackLinuxElf32::elf_lookup() at p_lx_elf.cpp:5382.
Frequently asked questions
- What is CVE-2021-43311?
- A heap-based buffer overflow was discovered in upx, during the generic pointer 'p' points to an inaccessible address in func get_le32(). The problem is essentially caused in PackLinuxElf32::elf_lookup() at p_lx_elf.cpp:5382.
- How severe is CVE-2021-43311?
- CVE-2021-43311 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
- Is CVE-2021-43311 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (53rd percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2021-43311?
- CVE-2021-43311 affects Upx. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2021-43311?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- When was CVE-2021-43311 published?
- CVE-2021-43311 was published on 2023-03-24 and last updated on 2026-06-17.
References
Affected products (1)
- cpe:2.3:a:upx:upx:*:*:*:*:*:*:*:*
More vulnerabilities in Upx
- CVE-2020-27801 — High (CVSS 7.8): A heap-based buffer over-read was discovered in the get_le64 function in bele.h in UPX 4.0.0 via a crafted Mach-O file.
- CVE-2020-27800 — High (CVSS 7.8): A heap-based buffer over-read was discovered in the get_le32 function in bele.h in UPX 4.0.0 via a crafted Mach-O file.
- CVE-2020-27799 — High (CVSS 7.8): A heap-based buffer over-read was discovered in the acc_ua_get_be32 function in miniacc.h in UPX 4.0.0 via a crafted…
- CVE-2020-27796 — High (CVSS 7.8): A heap-based buffer over-read was discovered in the invert_pt_dynamic function in p_lx_elf.cpp in UPX 4.0.0 via a…
- CVE-2021-30500 — High (CVSS 7.8): Null pointer dereference was found in upx PackLinuxElf::canUnpack() in p_lx_elf.cpp,in version UPX 4.0.0. That allow…
- CVE-2019-14296 — High (CVSS 7.8): canUnpack in p_vmlinx.cpp in UPX 3.95 allows remote attackers to cause a denial of service (SEGV or buffer overflow,…
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